Giant magnetotransmission and magnetoreflection in ferromagnetic materials

Journal of Magnetism and Magnetic Materials 383 (2015) 104–109

Contents lists available at ScienceDirect

Journal of Magnetism and Magnetic Materials journal homepage: www.elsevier.com/locate/jmmm

Giant magnetotransmission and magnetoreflection in ferromagnetic materials A.V. Telegin a,n, Yu.P. Sukhorukov a, N.N. Loshkareva a, E.V. Mostovshchikova a, N.G. Bebenin a, E.A. Gan'shina b, A.B. Granovsky b a b

M.N. Miheev Institute of Metal Physics of Ural Branch of RAS, 620137 Yekaterinburg, Russia Moscow State University, 119991 Moscow, Russia

art ic l e i nf o

a b s t r a c t

Article history: Received 19 June 2014 Received in revised form 27 November 2014 Accepted 30 November 2014 Available online 5 December 2014

We present a brief review on magnetotransmission (magnetoabsorption) and magnetoreflection of natural (unpolarized) light in ferromagnetic chromium chalcogenide spinel, manganites with perovskite structure and thin-film metallic nanostructures in the middle infrared spectral range. The magnetooptical effects under discussion are of high interest for numerous and promising applications in the infrared optoelectronics. & 2014 Elsevier B.V. All rights reserved.

Keywords: Magnetotransmission Magnetoreflection Magnetoresistance Infrared Manganites Spinel Ferromagnetic Nanostructures Functional magnetooptical materials Films

1. Introduction Discovery of the magnetooptical Faraday effect in 1845 [1] started with the experimental research of the interaction of polarized electromagnetic radiation with various materials (vapors [2], liquids [3], metals [4], semiconductors [5], dielectrics [6]). A large number of even and odd (with respect to magnetization) magnetooptical (MO) effects in linear and circular polarized light has been revealed [7,8]. All the effects are widely used in fundamental research of magnetic materials as well as in practice [9–11]. The MO effects are found in the wide spectral range from radioand microwave frequencies to X-ray [4–8,12–14]. It is important that the changes in the optical properties (transmission t or reflection R) in external magnetic field H are observed even in the case of unpolarized (natural) light. These effects are called magnetotransmission Δt/t¼[t(H)  t(0)]/t(0) and magnetoreflection ΔR/R¼ [R(H) R(0)]/R(0), respectively. To this group the following MO effects belong: (1) magneto-plasma effect n Correspondence to: IMP, S. Kovalevskaya Street 18, 620137 Yekaterinburg, Russia. E-mail address: [email protected] (A.V. Telegin).

http://dx.doi.org/10.1016/j.jmmm.2014.11.080 0304-8853/& 2014 Elsevier B.V. All rights reserved.

associated with the shift of position of the plasma frequency in semiconductors, metals, and semimetals in a magnetic field [5,15]; (2) cyclotron resonance associated with the resonant absorption or reflection of electromagnetic waves by a semiconductor, semimetal or metal at the cyclotron frequency of charge carriers [16,17]; (3) the Shubnikov-de Haas resonance effect, which manifests itself in the form of oscillations of ΔR/R on the background of magneto-plasma effect in semiconductors and metals due to the quantization of the orbital motion of charge carriers in a magnetic field [16,17]; and (4) magnetoreflection and magnetotransmission associated with the interband allowed transitions between Landau levels in semiconductors and metal films [5] that can be seen as oscillations at a fixed frequency in a variable magnetic field. As a rule, all the MO effects in natural light are weak appearing in narrow spectral intervals in high magnetic fields at low temperatures. The exchange interaction of electrons with local magnetic moments results in the significant changes in the band structure of a ferromagnet (FM) and enhances the effect of magnetic field on optical properties. In 1966 the giant “red” shift of the absorption edge was discovered in EuO and EuSe [18]. This pioneering work began studying Δt/t and later ΔR/R in magnetic materials in

A.V. Telegin et al. / Journal of Magnetism and Magnetic Materials 383 (2015) 104–109

105

unpolarized light. It was shown that Δt/t and ΔR/R can be as large as several tens of percent in FMs in rather weak magnetic fields and in wide spectral and temperature ranges. In this paper we shortly review the results of the study of the Δt/t and ΔR/R effects in FM spinels HgCr2Se4 (Curie temperature TC ¼110 K) and CdCr2Se4 (TC ¼130 K) of n-and p-type, manganites AxB1  xMnO3 (where A is rare-earth, B is alkaline metals) of perovskite structure, and in multilayered Fe/Cr nanostructures.

2. Ferromagnetic chromium chalcogenide spinels Fig. 1a shows the spectra of the reflectivity for the undoped HgCr2Se4 single crystals of p- and n-type in comparison with the spectra of spinel with free charge carriers at room temperature [19,20] and T¼ 4.2 K [21]. The substitution of Hg by Cd with close ionic radius, which remains lattice constant unchanged, weakly changes the spectrum at the wavelength λ o35 μm [20,22] if there is no charge carriers. The difference between the spectra of n- and p-HgCr2Se4 is due to the different plasma frequency, which is ωp E4.25  1013 s  1 (λ ¼7.5 mm) for p-HgCr2Se4 and ωp E2.3  1013 s  1 (λ ¼13 mm) for n-HgCr2Se4 [19,20]. It should be noted that application of a magnetic field gives rise to change in reflectivity of a spinel (about 1% for HgCr2Se4 single crystal). Fig. 1b shows the absorption coefficient α versus λ. At λ o3.5 μm we see sharp rise of absorption due to the fundamental edge. At T oTC the absorption spectra are due to transition from the valence band formed mainly by 4pSe states to the conduction band, which is formed by 4sCrþ6sHg in the case of HgCr2Se4 with energy gap being about 0.3 eV, or 4sCr þ5sCd states for CdCr2Se4 with the gap of about 1.1 eV [23]; at longer wavelengths the impurity absorption is responsible for absorption [24,25]. In the paramagnetic state, the transition responsible to the absorption edge are the same as in the ferromagnetic state in the case of HgCr2Se4, the energy gap being about 0.8 eV at T»TC; in CdCr2Se4, however, the edge is due to transition from the valence band into so called p-dγ band (4pSe þ3dγCr), the gap being increased up to 1.3 eV [23,26]. Magnetic field significantly affects the absorption spectrum (Inset in Fig. 1b). Fig.2 shows the spectra of ΔR/R and Δt/t of HgCr2Se4 single crystals. The magnitude and sign of the effect depend on the type of conductivity of spinel [26]. The complex shape of the ΔR/R spectra for HgCr2Se4 (Fig.2a) is

Fig. 1. (a) Spectra of the reflectivity of undoped Hg(Cd)Cr2Se4 crystals [20], p-type Hg0.98Ag0.02Cr2Se4 ceramics [19] at room temperature and n-type HgCr2Se4 at T ¼ 4 K [21]; and (b) absorption coefficient at T ¼ 300 K. Inset: effect of magnetic field on absorption coefficient.

Fig. 2. (a) Spectra of the magnetoreflection ΔR/R of the HgCr2Se4 single crystals at T ¼80 K for p-type and T ¼TC for n-type (magnetic field of 3.5 kOe is in plane of the sample surface); (b) magnetotransmission Δt/t in out-of-plane (1) and in-plane (2) magnetic field of 8 kOe. Insets: temperature dependences of ΔR/R and Δt/t for n-HgCr2Se4 (open symbols) and p-HgCr2Se4 (filled symbols) taken at wavelength corresponding to the maximum of the MO effects.

due to the “red” shift of the absorption edge at λ o3.5 μm and interaction of light with free charge carriers at λ 4 3 μm. The former one reduces the effect in the vicinity of λ ¼3 μm until the change of sign. The second one leads to an increase of the effect up to maximum value at ω E 3  1013 s  1 (λ ¼ 10 μm). This phenomenon can be explained in the framework of theory of the magnetorefractive effect for magnetic materials with giant magnetoresistance [27] according to which the ΔR/R should reach a maximum at ωτ  1 (e.g. for p-HgCr2Se4 τ ¼ 2.3  10  14 s). The observed difference in ΔR/R at the wavelength λ 43 μm may be connected with the difference in concentrations of charge carriers for p- and n-type samples. The magnetotransmission effect in HgCr2Se4 can reach giant values (up to 80%) in low magnetic fields in a wide infrared range (for example, Fig. 2b) [28]. The shape of the Δt/t spectra as well as the magnitude and sign of the effect are determined by different contributions: the “red” shift of the absorption edge takes place at λ o3.5 μm, optical transitions in the VSe–Cr2 þ complexes are seen in the 4–6 μm band, the interaction of light with free charge carriers dominates in the wavelength range of 6 o λ o 20 μm. Both the type of the conductivity and carrier concentration are also important [23–26]. The direction of a magnetic field relative to the crystallographic axes can also influence the magnitude of Δt/t in the case of p-type spinels [26]. The Δt/t as well as ΔR/R are positive in n- and p-HgCr2Se4 at λ 43 μm (Figs.2a and 2b). In Hg1-xCdxCr2Se4 the substitution of Hg by Cd leads to the narrowing of the spectral range where the magnetotransmission is observed. The Δt/t decreases with increasing x, the shape of the curves Δt/t being changed and the Δt/t peak shifted at 0.25 ox o1. The reason is the shift of the absorption band [26]. The change of the Δt/t spectrum of Hgx  1CdxCr2Se4 can be due to the decrease of the contribution related to the free charge carriers and to the transformation of the electron structure because of the substitution of Cd for Hg. In addition, the mechanical stresses arising in the course of the crystal growth can also vary at different Cd contents. The temperature dependences of ΔR/R and Δt/t for p-HgCr2Se4 (Insets in Fig. 2) are similar to that of magnetization. On the contrary, for n-type HgCr2Se4 spinel magnetoreflection as well as magnetotransmission reaches a maximum near TC (insets in Fig. 2). The observed difference in temperature behavior of ΔR/R

106

A.V. Telegin et al. / Journal of Magnetism and Magnetic Materials 383 (2015) 104–109

and Δt/t, depending on the type of conductivity, can be explained by a much stronger exchange interaction of the free charge carriers with localized magnetic moments in the (4sCrþ6sHg) conduction band for n-type spinel in comparison to that in the valence band formed mainly by the 4pSe states for p-type spinel [23]. The ΔR/R and Δt/t effects are even relative to a magnetic field. Magnetic field dependences of Δt/t for p-HgxCd1  xCr2Se4 are similar to the magnetization. At λ o3 μm near the absorption edge, an extra negative contribution to Δt/t appears due to the “red” shift of the absorption edge [28].

3. Ferromagnetic manganites with colossal magnetoresistance The negative magnetotransmission effect was discovered in manganites with colossal magnetoresistance (CMR) in 1997 [29]. The value of Δt/t is maximal in the vicinity of TC as well as that of magnetoresistance. In 1999 positive magnetoreflection effect was also found in CMR manganites [30]. Both the effects were studied in single crystals, polycrystals, thin films, heterostructures, multilayers, and optical composites based on manganites [31–36]. It was shown theoretically [36] that in manganites the ΔR/R and Δt/ t effects are optical responses on colossal magnetoresistance in the infrared spectral region. The main papers devoted to the study of ΔR/R and Δt/t in the manganites represent data for infrared range where these effects are predominantly associated with the interaction of light with both localized and delocalized charge carriers [37–40]. A positive magnetoreflection in single crystalline manganites reaches several percent [41] (Fig. 3a); in the films of the same composition the effect is higher due to multiple reflections of light from the film–substrate boundary [42]. Sample surface roughness and impurity distribution across the skin-depth or along the surface of crystal may also affect the magnetoreflection. In the thin strained films and the thin-film heterostructures the resonancelike contributions to ΔR/R spectra arise due to the displacement of the reflectivity minimum in a magnetic field (Fig. 3a). This peculiarity is the most pronounced near the first phonon band of

Fig. 3. (a) Spectra of magnetoreflection ΔR/R for the La0.7Ca0.3MnO3 single crystal (multiply by five times) (1), La0.7Ca0.3MnO3 films with thicknesses d ¼300 nm (2) and d ¼50 nm (3), La0.85K0.10MnO3 film [44] in in-plane magnetic field of 3.5 kOe (4); (b) magnetotransmission Δt/t for La0.9Sr0.1MnO3 single crystal (1) [29], polycrystal (2) and thin film of La0.85K0.10MnO3 (3) and La0.7Са0.3MnO3 film (4) in the magnetic field of 8 kOe applied out of sample surface. All the data is taken at temperatures corresponding to maximum effects.

reflection spectra of manganites. The value of this resonance-like contribution depends on the manganite inhomogeneity and differs for films of different thicknesses [27,41,42]. Negative magnetotransmission can be as large as some tens of percent in the CMR manganites in wide IR region (Fig. 3b). Magnetotransmission is determined by the volume of FM phase, type and level of doping, and inhomogeneity of a manganite [43]. Therefore the temperature and field dependences of magnetotransmission are quite different at different wavelengths. Moreover, the magnitude of magnetotransmission depends on the film thickness, the mechanical stresses, and the interface phenomena [27,41–44]. Notice that because of quasi-local character of the magnetotransmission (different optical responses from conducting and non-conducting areas) the Δt/t measurements are a good tool for studying the magnetic and charge inhomogeneity in CMR materials [45,46]. Very large values of ΔR/R and Δt/t are found in the manganites in which the ferromagnetic-to-paramagnetic phase transition is of the first order, for example, (La1  xPrx)0.7Ca0.3MnO3 [43]. The effects are even with respect to the magnetic field and occur in narrow temperature region around TC (Fig. 4), showing no hysteresis and saturation in fields up to 10 kOe (see Insets in Fig. 4). Charge and magnetic inhomogeneities lead to the decrease of the magnitude of the effects and give rise to additional features in the temperature and magnetic field dependences (e.g. hysteresis) [43–47]. Besides magnetic field, an electric field can also influence the magnetic order and therefore change the magnetotransmission [48]. As the magnitude of ΔR/R and Δt/t reaches tens of percent (Figs. 3 and 4) in rather low magnetic fields, they may be called giant. The temperature and field dependences of ΔR/R and Δt/t in the manganites are similar to those of magnetoresistance, which indicates that ΔR/R and Δt/t effects show optical response to CMR in the infrared range. It corresponds to the theory of magnetorefractive (MRE) effect (intrinsic MRE [49]) developed and applied for manganites [27,50]. In this theory the following relations were derived

Fig. 4. (a) Temperature dependences of magnetoreflection ΔR/R for the La0.85K0.15MnO3 (solid line) and La0.7Ca0.3MnO3 films (squares) at λ ¼ 13.5 μm at inplane magnetic field of 3.5 kOe; (b) magnetotransmission Δt/t for the La0.7Са0.3MnO3 and La0.85K0.15MnO3 films at λ¼ 6 μm at out-of-plane magnetic field of 8 kOe. Insets: magnetic field dependences of ΔR/R and Δt/t for La0.7Са0.3MnO3 film taken at the temperature of maximum of the effects.

A.V. Telegin et al. / Journal of Magnetism and Magnetic Materials 383 (2015) 104–109

107

due to the concentration of magnetic flux in the manganite layer [55] or to receive a practically temperature-independent magnetotransmission in the heterostructure consisting of the layers with different TC [56]. All these efforts aimed at development of novel multifunctional magneto-optical materials and resulted in promising applications [39,57,58].

4. Ferromagnetic multilayer Fe/Cr nanostructures

Fig. 5. Calculated spectra of magnetoreflection ΔR/R and magnetotransmission Δt/t for La0.7Са0.3MnO3 film (d ¼ 300 nm) at different volume fraction of the conductivity phase y in a magnetic field of 8 kOe near TC [50].

ΔR = − (1 − R)MRk 2[(3n2 − k 2 − 1)/{(n2 + k 2)[(1 − n)2 + k 2]}], R

(1)

Δt 1 = MRtk 2(2n2 + n)/(n2 + k 2), t 2

(2)

Magnetotransmission and magnetoreflection effects in systems with tunneling magnetoresistance and giant magnetoresistance due to magnetic phase transitions are accepted to associate with the magnetorefractive (MRE) effect [27,49,59,60]. In the framework of the MRE theory an applied magnetic field influences the conductivity of a multilayer and thereby changes the dielectric constant as well as indexes of refraction defining the reflection and transmission of light. To describe the MRE one usually needs to build an effective dielectric structure in the framework of selfaveraging approaching taking into account the processes of spindependent scattering both in the bulk of the layers and at the interfaces. This approach has been very successful to explain the MRE in granular alloys and nanocomposites [59]. It was shown that one can receive giant ΔR/R and Δt/t effects in the IR region of up to some percents in metal thin-film multilayer structures, granular metallic films and photonic crystals, having enormous MR, in the IR range [27,59–61]. In those studies, ΔR/R and Δt/t were defined as parameters of the MRE related to the magneticfield-induced change of the permittivity (ε), and consequently, the 2

where MR stands for magnetoresistance, n and k are the refractive indexes. Comparison of the experimental data in the infrared range (Fig. 3) with the results of calculations (Fig. 5) indicates that the expressions (1) and (2) are applicable only to optimally doped compounds [43]. In other – more usual – cases the effective medium consisting of regions with different conductivities should be considered [50]. Unfortunately, the effective medium approach or the intrinsic MRE theory provides no more than qualitative agreement with experiment (Fig. 5) and do not explain some important details of magnetoreflection and magnetotransmission in manganites. It follows that in addition to the above considered mechanism of the MRE some other features of manganites should be taken into account, for example, the change of electronic structure under magnetization and influence of magnetic field on polarons [51]. In the visible spectral range magnetoreflection and magnetotransmission in manganites have a different nature as compared to the effects observed in the IR range [33,52]. The values of the effects are small (about 1–2% in a magnetic field of 8 kOe), have a weak temperature dependence and exist above TC [33]. The origin of the effects is currently under debate and several mechanisms working in competition can be considered as possible candidates for explanation: (1) influence of the magnetic field on interband transitions; (2) suppression of the Jahn–Teller effect in a magnetic field; (3) even-parity MO effects; and (4) influence of the magnetic field on the non-magnetic and magnetic polarons, etc. Magnetotransmission and magnetoreflection were studied in the thin-film heterostructures and multilayers of manganites where the crucial influence of the interface on ΔR/R and Δt/t was established [32,34,53]. It was shown that there is a possibility to gain in magnetotransmission in multilayers, for example, in the ferrite/manganite heterostructure due to biasing of manganite layer by ferrite one [54], in the heterostructure HTSC/manganite

complex refractive indexesε = n = (n − ik)2. It should be noted that at present there is, however, a misleading with using the term MRE as a simple synonym of the magnetotransmission and magnetoreflection effects independently of the magnetic and electrical properties of the materials under study. Figs. 6 and 7 show the ΔR/R and Δt/t spectra for the sevenlayer Fe/Cr nanostructure [62]. Unlike manganites with negative Δt/t and magnetoresistance, the magnetotransmission of the Fe/Cr is positive, despite the negative MR. In contrast to the magnetotransmission spectrum, ΔR/R is negative (just as MR), takes place in a narrow wavelength range and does not exceed 0.4% (Fig.6). In spite of the increasing MR value as the temperature decreases to 70 K, ΔR/R and Δt/t become weakly temperature dependent. The field dependences of the ΔR/R and Δt/t demonstrate an even

˘

Fig. 6. Spectra of the magnetotransmission Δt/t of the Fe/Cr nanostructure in outof-plane magnetic field H¼ 8 kOe and magnetoreflection ΔR/R at in-plane H¼2.2 kOe at T ¼300 K. Dashed lines are the results of calculations from MRE theory. Inset: field dependence of ΔR/R at T ¼300 K.

108

A.V. Telegin et al. / Journal of Magnetism and Magnetic Materials 383 (2015) 104–109

to utilize both gyrotropic and nongyrotropic effects in one device. The magnetoreflection makes possible a fast effective control of MR of the key elements of spintronics (e.g. spin-valves) during their mass-production. Besides technical applications, the magnetoreflection and magnetotransmission of light can be used in physics for contactless investigation of MR in nanostructures, spin asymmetry, high-frequency tunneling, surface inhomogeneity, magnetic and non-magnetic polarons, etc.

6. Conclusions

Fig. 7. Field dependences of the magnetotransmission Δt/t and magnetoresistance MR of the Fe/Cr nanostructure at T ¼300 K in out-of-plane (1) and in-plane (2) magnetic field.

effect and a tendency toward an increase in the magnitude with increasing field. Although the MRE theory qualitatively describes the sign, spectral and field dependences of the magnetotransmission and magnetoreflection (Figs. 6 and 7), calculated ΔR/R and Δt/t do not agree well with the experimental results, in particular, near the visible region. It can be explained by the fact that the ΔR/R and Δt/t in the nanostructures as well as magnetotransmission in the manganites in visible range can also be controlled by other mechanisms in the middle infrared, such as the action of a magnetic field on the electronic structure, the carrier concentration and the interband transition intensity. For example, the negative ΔR/R and positive Δt/t of Cr/Fe nanostructure at 2 o λ o6 μm are most likely related to the change of the electronic structure defining the interband transition in Fe [63] when the mutual orientation of the magnetic moments of the layers in a magnetic field is modified. Lobov et al. [64] showed that further increase of λ leads to the undergoing changes of sign and magnitude of ΔR/R. So, the MRE theory based on the concept of self-averaging is inapplicable and one should use an ab initio approach or multiband strongcoupling models for describing ΔR/R and Δt/t in the Fe/Cr multilayer.

5. Possible applications of the magnetotransmission and magnetoreflection of light Comparing the magnetoreflection and magnetotransmission and conventional magnetooptical effects (Faraday, Kerr effects) in ferromagnetics one can conclude that ΔR/R and Δt/t are some orders of magnitude larger in the IR range and can also be by several times larger in the visible range [33]. Being quite large, in some cases up to 50%, which is giant for magneto-optics, nongyrotropic, independent of orientation of magnetic field and light polarization at small angles of light incidence, the magnetoreflection and magnetotransmission can be successfully used in magnetophotonic. In particular, the giant magnetotransmission and magnetoreflection of light in the CMR manganites allowed recommending these ferromagnetic materials for practical applications, for example, creating magnetic “lens”, infrared radiation modulators, high-frequency optical isolators and attenuators, temperature indicators and so on [33,35,39,52,54–58]. Since the manganites exhibit strong magnetooptical response, it is possible

Significant progress in studying the magnetoreflection and magnetotransmission of natural light in different ferromagnetic structures exhibiting giant and colossal magnetoresistance has been achieved in the last years. It is shown that for the middle infrared spectral region these effects are mainly associated with the high-frequency magnetoresistance and can be satisfactory described in the framework of the theory of the magnetorefractive effect. A number of different mechanisms are responsible for magnetoreflection and magnetotransmission of light in spinels, manganites and metallic nanostructures. Despite of different origins, the observed effects are one or two orders of magnitude greater than the conventional magnetooptical phenomena in the infrared. Being quite large, magnetoreflection and magnetotransmission effects in ferromagnetic structures are successfully used in optoelectronics. However, many problems are still unclear, for example, polarization and angle dependence of magnetoreflection and magnetotransmission. We hope that our brief review will stimulate further experimental and theoretical study of the interaction of light in various magnetic structures.

Acknowledgments This work was partially supported by the Russian Foundation for Basic Research No. 13-02-00007, by the Presidium of Russian Academy of Sciences and by the Megagrant RF No. 14.Z50.31.0025.

References [1] M. Faraday, Experimental researches in electricity, Phil. Trans. R. Soc. 136 (1846) 1–20. [2] T.Ya Karagodova, A.V. Kuptsova, Faraday effect in alkali-metal vapors in a strong bichromatic field of laser light, Opt. Spectrosc. 92 (2002) 487–491. [3] A.A. Spartakov, АА Trusov, A.V. Voitylov, V.V. Vojtylov, Electro-optics of polydisperse colloids, in: S. Stoylov, M. Stoimenova (Eds.), Molecular and Colloidal Electro-Optics, CRC Press, London, New York, 2006. [4] V. Yu., M.M. Knyazev, Noskov, The optical properties of rare earth metals, Phys. State Solidi (B) 80 (1977) 11–29. [5] R.K. Wilardson, A.C. Beer, Semiconductos and Semimetals, Academic press, New York and London, 1967. [6] G.A. Smolenskii, Magneto-optical and radiospectroscopic investigations of magnetic and dielectric crystals, Sov. Phys. Usp. 14 (1972) 542–543. [7] J. Kerr, On rotation of the plane of polarization by reflection from the pole of a magnet, Philos. Magn. 3 (1877) 321–343. [8] W. Voigt, Electro- and Magneto-Optics, Teubner, Leipzig, 1907. [9] E.P. Mustel, V.N. Parygin, Metody moduliatsii i skanirovaniia sveta, Nauka, Moscow, 1970 (in Russian). [10] V.V. Randoshkin, A.Ya Chervonenkis, , Applied Magnetooptics, Energoatomizdat, Moscow, 1991 (in Russian). [11] A.K. Zvezdin, V.A. Kotov, Modern Magnetooptics and Magnetooptical Materials, Institute of Physics, London, 1997. [12] V.V. Gudkov, J.D. Gavenda, Magnetoacoustic Polarization Phenomena in Solids, Springer-Verlag, New York, 2000. [13] R.R. Mansfield, M.R. Borst, The microwave Faraday effect in indium antimonide, Br. J. Appl. Phys. 16 (1965) 570–575. [14] S.G. Ovchinnikov, Application of synchrotron radiation to the study of magnetic materials, Phys. Usp. 42 (1999) 779–796. [15] B. Lax, J.G. Mavroides, Cyclotron resonance, in: F. Seitz, D. Turnbull (Eds.), Solid State Physics, Academic Press, New York, 1960. [16] S.V. Vonsovskii, Magnetism, J. Wiley, New York, 1974.

A.V. Telegin et al. / Journal of Magnetism and Magnetic Materials 383 (2015) 104–109

[17] I.M. Tsidilkovski, Band structure of semiconductors, Int. Ser.Sci. Solid State (1982). [18] M.J. Freiser, F. Holtzberg, S. Methfessel, G.D. Pettit, M.W. Shafer, J.C. Suits, The magnetic red shift in europium chalcogenides, Helv. Phys. Acta 41 (1968) 832–838. [19] N.N. Loshkareva, N.B. Bebenin, B.A. Gizhevskii, YuP. Sukhorukov, Effective mass of holes in the ferromagnetic semiconductor HgCr2Se4, Sov. Phys. Solid State 34 (1992) 1760–1761. [20] D. Bonnerberg, K.A. Hempel, R.A. Lefer, T.R. McGuire, M. Paulus, H. von Philipsborn, M. Rubinstein, M. Sugimoto, L. Treitinger, R. Vautier, Spinels, Fe oxides, and Fe–Me–O compounds, in: K.-H. Hellwege, A.M. Hellwege (Eds.), Magnetic and Other Properties of Oxides and Related Compounds, SpringerVerlag, Berlin, Heidelberg, NewYork, 1980. [21] A. Selmi, R. Le Toullec, R. Raymonville, Influence of the spin disorder on the plasma edge in n-type HgCr2Se4, Phys. Status Solidi (B) 114 (1982) K97–K99. [22] T. Rudolf, Ch Kant, F. Mayr, J. Hemberger, V. Tsurkan, A. Loidl, Polar phonons and spin–phonon coupling in HgCr2Se4 and CdCr2Se4 studied with far-infrared spectroscopy, Phys. Rev. B 76 (2007) 174307-1–174307-10. [23] M.I. Auslender, N.G. Bebenin, On the band structure and anisotropy of transport properties of ferromagnetic semiconductors CdCr2Se4 and HgCr2Se4, Solid State Commun. 69 (1989) 761–764. [24] N.N. Loshkareva., YuP. Sukhorukov, B.A. Gizhevskii, M.I. Simonova, T. G. Aminov, A.A. Samochvalov, Impurity light absorption in chromium chalcogene spinel, Fiz. Tverd. Tela 27 (1985) 3462–3464 (in Russian). [25] N.N. Loshkareva., YuP. Sukhorukov, B.A. Gizhevskii, N.M. Chebotaev, M. I. Simonova, A.A. Samochvalov, Absorption spectra of nonstoichiometric single crystals of magnetic semiconductor HgCr2Se4, Fiz. Tverd. Tela 29 (1987) 2231–2233 (in Russian). [26] M.I. Auslender, E.V. Barsukova, N.G. Bebenin, B.A. Gizhevskii, N.N. Loshkareva, YuP. Sukhorukov, N.M. Chebotaev, Absorption spectrum of n- and p-type single crystals of ferromagnetic semiconductor HgCr2Se4 in a magnetic field, Sov. Phys. JETP 68 (1989) 139–142. [27] A. Granovsky, Yu Sukhorukov, E. Gan’shina, A. Telegin, Magnetorefractive effect in magnetoresistive materials, in: M. Inoue, M. Levy, A.V. Baryshev (Eds.), Magnetophotonics: From Theory to Applications, Springer Verlag, Berlin, 2013. [28] P. Yu., A.V. Sukhorukov, N.G. Telegin, E.I. Bebenin, S.V. Patrakov, V.A. Naumov, T.K. Fedorov, Menshchikova, Magnetotransmission of unpolarized infrared radiation in Hg1–xCdxCr2Se4 (0r x r1) single crystals studied using the Voigt geometry, JETP Lett. 98 (2013) 313–316. [29] N.N. Loshkareva, YuP. Sukhorukov, B.A. Gizhevskii, A.A. Samokhvalov, V. E. Arkhipov, V.E. Naish, S.G. Karabashev, YaM. Mukovskii, Red shift of absorption edge and nonmetal-metal transition in single crystals La1–xSrxMnO3 (x¼ 0.1, 0.2, 0.3), Phys. Stat. Sol. (a) 164 (1997) 863–867. [30] A.V. Boris, N.N. Kovaleva, A.V. Bazhenov, P.J.M. van Bentum, Th Rasing, S.W. Cheong, A.V. Samoilov, N.-C. Yeh, Infrared studies of a La0.67Ca0.33MnO3 single crystal: optical magnetoconductivity in a half-metallic ferromagnet, Phys. Rev. B. 59 (1999) R697–R700. [31] E. Ganshina, N. Loshkareva, Yu Sukhorukov, E. Mostovshchikova, A. Vinogradov, L. Nomerovannaya, Optical and magneto-optical spectroscopy of manganites, J. Magn. Magn. Mater. 300 (2006) 62–66. [32] P. Yu., A.V. Sukhorukov, E.A. Telegin, E.A. Gan'shina, A.N. Stepantsov, F. Vinogradov, D. Lombardi, Winkler, Effect of an interface boundary on the magnetooptical and magnetotransport properties of La0.67Ca0.33MnO3 /La0.67Sr0.33MnO3 heterostructures, Tech. Phys. 55 (2010) 1161–1167. [33] YuP. Sukhorukov, A.V. Telegin, A.B. Granovskii, E.A. Gan'shina, A. Zukov, J. Gonsalez, G. Herranz, J.M. Caicedo, A.N. Yurasov, V.D. Bessonov, A.R. Kaul, O. Yu Gorbenko, I.E. Korsakov, Magnetorefractive effect in manganites with a colossal magnetoresistance in the visible spectral region, J. Exp. Theor. Phys. 114 (2012) 141–149. [34] YuP. Sukhorukov, A.V. Telegin, E.A. Gan'shina, E.A. Stepantsov, R. Gunnarsson, V.D. Bessonov, F. Lombardi, Magnetorefractive effect in La2/3Ca1/3MnO3 /La2/3Sr1/3MnO3 heterostructures, J. Spintron. Magn. Nanomater. 1 (2012) 139–146. [35] A.V. Telegin, E.V. Mostovshchikova, V.D. Bessonov, S.V. Telegin, B.A. Gizhevskii, Infrared magneto-optical composite materials based on manganite powders, J. Appl. Phys. 113 (17A932) (2013) 1–3. [36] A.B. Granovskii, E.A. Gan'shina, A.N. Yurasov, YuV. Boriskina, S.G. Yerokhin, A. B. Khanikaev, M. Inoue, A.P. Vinogradov, YuP. Sukhorukov, Magnetorefractive effect in nanostructures, manganites, and magnetophotonic crystals based on these materials, J. Commun. Technol. Electron. 52 (2007) 1065–1071. [37] Y. Okimoto, Y. Tokura, Optical spectroscopy of perovskite-type manganites, J. Supercond. Inc. Novel Magn. 13 (2000) 271–284. [38] H.J. Lee, K.H. Kim, T.W. Noh, B.G. Kim, T.Y. Koo, S.-W. Cheong, Y.J. Wang, X. Wei, Optical evidence of multiphase coexistence in single crystalline (La,Pr,Ca) MnO3, Phys. Rev. B. 65 (115118) (2002) 1–6. [39] R.F.C. Marques, P.R. Abernethy, J.A.D. Matthew, Carlos O. Paiva-Santosa, L. Perazollia, M. Jafelicci Jr.a, S.M. Thompson, Contactless measurement of colossal magnetoresistance in La1  xSrxMnO3 using the infrared magnetorefractive effect, J. Magn. Magn. Mater., 272–276, 1740–1741. [40] M. Fiebig, K. Miyano, Y. Tomioka, Y. Tokura, Reflection spectroscopy on the photoinduced local metallic phase of Pr0.7Ca0.3MnO3, J. Appl. Phys. 74 (1999) 2310–2312. [41] YuP. Sukhorukov, A.V. Telegin, A.B. Granovsky, E.A. Gan'shina, S.V. Naumov, L.

[42]

[43]

[44]

[45]

[46]

[47]

[48]

[49]

[50]

[51]

[52]

[53]

[54]

[55]

[56]

[57]

[58]

[59]

[60]

[61]

[62]

[63] [64]

109

V. Elokhina, J. Gonzalez, Magnetorefractive effect in La0.7Ca0.3MnO3 in the infrared spectral range, J. Exp. Theor. Phys. 111 (2010) 353–360. A.B. Granovsky, YuP. Sukhorukov, A.V. Telegin, V.D. Bessonov, E.A. Gan'shina, A.R. Kaul, I.E. Korsakov, O.Yu Gorbenko, J. Gonzalez, Giant magnetorefractive effect in La0.7Ca0.3MnO3 films, JETP 112 (2011) 77–86. YuP. Sukhorukov, N.N. Loshkareva, E.A. Gan'shina, A.R. Kaul, O.Yu Gorbenko, E. V. Mostovshchikova, A.V. Telegin, A.N. Vinogradov, I.K. Rodin, Effect of isovalent doping of manganite (La1  xPrx)0.7Ca0.3MnO3 films (0 r xr 1) on their optical, magnetooptical, and transport properties near the metal–insulator transition, Phys. Solid State 46 (2004) 1241–1251. YuP. Sukhorukov, A.V. Telegin, V.D. Bessonov, E.A. Gan'shina, A.R. Kaul, I. E. Korsakov, N.S. Perov, L.Yu Fetisov, A.N. Yurasov, Magnetorefractive effect in the La1  xKxMnO3 thin films grown by MOCVD, J. Magn. Magn. Mater. 367 (2014) 53–59. N.N. Loshkareva, A.V. Korolev, T.I. Arbuzova, N.I. Solin, N.A. Viglin, I.B. Smolyak, N.G. Bebenin, YuP. Sukhorukov, S.V. Naumov, N.V. Kostromitina, A. M. Balbashov, Charge segregation and a nonuniform magnetic state in donorand acceptor-doped LaMnO3, Phys. Solid State 44 (2002) 1916–1924. YuP. Sukhorukov, N.N. Loshkareva, E.V. Mostovshchikova, A.S. Moskvin, E. V. Zenkov, E.A. Gan'shina, I.K. Rodin, A.R. Kaul, O.Yu Gorbenko, A.A. Bosak, Phase separation and electronic structure in LaxMnO3 (0.83 r xr 1.10) films, J. Magn. Magn. Mater. 258–259 (2003) 274–276. O.V. Melnikov, YuP. Sukhorukov, A.V. Telegin, E.A. Gan'shina, N.N. Loshkareva, A.R. Kaul, O.Yu Gorbenko, A.N. Vinogradov, I.B. Smoljak, The evolution of magneto-transport and magneto-optical properties of thin La0.8Ag0.1MnO3 þ δ films possessing the in-plane variant structure as a function of the thickness, J. Phys.: Condens. Matter. 18 (2006) 3753–3765. P. Yu., N.N. Sukhorukov, A.S. Loshkareva, E.A. Moskvin, Gan, A.R. shina, O. Kaul, Yu Gorbenko, YaM. Mukovskii, Influence of magnetic and electrical fields on optical properties of lanthanum manganite films, Phys. Met. Metallogr. 91 (2001) 174–178. J.C. Jacquet, T. Valet, in: E. Marinero (Ed.), Proceedings of the Materials Research Society Magnetic Ultrathin Films, Multilayer and Surfaces, Materials Research Society, Pittsburg, 1995, p. 477. A.N. Yurasov, T.N. Bakhvalova, A.V. Telegin, YuP. Sukhorukov, A.B. Granovsky, The analysis of the magnetorefractive effect in La0.7Ca0.3MnO3: thin films and single crystals, Solid State Phenom. 190 (2012) 381–384. J.W. Lynn, C.P. Adams, Y.M. Mukovskii, A.A. Arsenov, D.A. Shulyatev, Charge correlations in the magnetoresistive oxide La0.7Ca0.3MnO3, J. Appl. Phys. 89 (2001) 6846–6850. D. Hrabovsk´y, G. Herranz, K. Postava, I.C. Infante, F. S´anchez, J. Fontcuberta, , Optical sensing of magnetic field based on magnetorefractive effect in manganites, Proc. SPIE 7356 (2009) (73560R1-73560R10). YuP. Sukhorukov, A.V. Telegin, A.P. Nosov, E.A. Gan'shina, E.A. Stepantsov, F. Lombardi, D. Winkler, Magnetorefractive and Kerr effects in the [La0.67Ca0.33MnO3/La0.67Sr0.33MnO3]n superlattices, J. Superlattices Microstruct. 75 (2014) 680–691. YuP. Sukhorukov, N.N. Loshkareva, E.A. Gan'shina, A.R. Kaul, A.A. Kamenev, O. Yu Gorbenko, A.V. Telegin, Magnetotransmission and magnetoresistance in film manganite/ferrite heterostructures, Phys. Met. Metallogr. 107 (2009) 579–587. A.R. Kaul, O.Yu Gorbenko, N.N. Loshkareva, YuP. Sukhorukov, E. V. Mostovshchikova, Magnetic lens based on the ferromagnetic manganites with high TC-superconductor heterostructure, Phys. Low-Dim. Struct. 7/8 (2003) 124–129. YuP. Sukhorukov, E.A. Gan'shina, A.R. Kaul, O.Yu Gorbenko, N.N. Loshkareva, A. V. Telegin, M.S. Kartavtseva, A.N. Vinogradov, Sm0.55Sr0.45MnO3  Nd0.55Sr0.45MnO3 heteroepitaxial structure: optical and magnetotransport properties, Tech. Phys. 53 (2008) 716–721. Yu.P. Sukhorukov, N.N. Loshkareva, O.Yu. Gorbenko, A.R. Kaul, A.V. Telegin, Method of Modulating Infrared Radiation, Patent RF of No. RU 88165 Bull. No. 36 27.10, 2009. T. Stanton, M. Vopsaroiu, S.M. Thompson, A portable instrument for noncontact giant magnetoresistance measurements utilizing the magnetorefractive effect and infrared fibres, Meas. Sci. Technol. 19 (125701) (2008) 1–7. A.B. Granovsky, M.V. Kuzmichev, J.P. Clerc, Optical and magnetooptical properties of granular alloys with giant magnetoresistance in the IR region of the spectrum, JETP 89 (1999) 955–959. S. Uran, M. Grimsditch, E.E. Fullerton, S.D. Bader, Infrared spectra of giant magnetoresistance Fe/Cr/Cr trilayers, Phys. Rev. B: Condens. Matter 57 (1998) 2705–2708. R.T. Mennicke, D. Bosec, V.G. Kravets, M. Vopsaroiu, J.A.D. Matthew, S. M. Thompson, Modelling the magnetorefractive effect in giant magnetoresistive granular and layered materials, J. Magn. Magn. Mater. 303 (2006) 92–110. V.V. Ustinov, YuP. Sukhorukov, M.A. Milyaev, A.B. Granovskii, A.N. Yurasov, E. A. Gan, shina, A.V. Telegin, Magnetotransmission and magnetoreflection in multilayer Fe/Cr nanostructures, JETP Lett. 108 (2009) 260–266. V.P. Shirokovskii, M.M. Kirillova, N.A. Shilkova, An optical absorption anomaly in iron, J. Exp. Theor. Phys. 55 (1982) 464–468. I.D. Lobov, M.M. Kirillova, L.N. Romashev, M.A. Milyaev, V.V. Ustinov, Study of scattering of conduction electrons in Fe/Cr superlattices by IR magnetoreflection method, Phys. Met. Metallogr. (2012) 1153–1161.