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Magnetization, magnetic susceptibility, effective magnetic moment of Fe3+ ions in Bi25FeO39 ferrite
Journal of Solid State Chemistry 212 (2014) 147–150
Contents lists available at ScienceDirect
Journal of Solid State Chemistry journal homepage: www.elsevier.com/locate/jssc
Magnetization, magnetic susceptibility, effective magnetic moment of Fe3 þ ions in Bi25FeO39 ferrite A.A. Zatsiupa a,n, L.A. Bashkirov a, I.O. Troyanchuk b, G.S. Petrov a, A.I. Galyas b, L.S. Lobanovsky b, S.V. Truhanov b a b
Belarussian State Technological University, 220030 Minsk, Belarus Scientific and Practical Materials Research Centre of the NAS of Belarus, 220072 Minsk, Belarus
art ic l e i nf o
a b s t r a c t
Article history: Received 20 April 2013 Received in revised form 13 January 2014 Accepted 15 January 2014 Available online 1 February 2014
Magnetic susceptibility for ferrite Bi25FeO39 is measured at 5–950 K in the magnetic field of 0.86 T. It is shown that Bi25FeO39 is paramagnetic in the temperature range 5 950 K. The saturation magnetization is equal to 5.04μB per formula unit at 5 K in a magnetic field of 10 T. It is found that at 5 300 K the effective magnetic moment of Fe3 þ ions in Bi25FeO39 is equal to 5.82μB. & 2014 Elsevier Inc. All rights reserved.
Keywords: Ceramics Crystal structure Magnetic susceptibility Effective magnetic moment of Fe3 þ Ferrite
1. Introduction It is known [1–5] that during interaction of bismuth oxide Bi2O3 with iron oxide Fe2O3 three compounds may be formed: Bi25FeO39, BiFeO3 and Bi2Fe4O9. Of these, bismuth ferrite BiFeO3 with the structure of rhombohedrally distorted perovskite is multiferroics, in which up to the Neel temperature (TN ¼643 K) at the same time there is an antiferromagnetic ordering of magnetic moments of Fe3 þ ions as well as the ordering of electric dipoles at temperatures below the Curie temperature (TC ¼1083 K) [6–8]. To date, many papers are published concerning the development of methods of preparation and study the properties of bismuth ferrite BiFeO3 and solid solutions based on it [4,9–16]. It is found that by means of solid-state reactions, the sol–gel and other methods, it is difficult to prepare single-phase samples of BiFeO3, and in most cases they contain a small amount of impurity phases of Bi25FeO39 and Bi2Fe4O9 ferrite, the presence of which distorts the results obtained. To take into account the effect of these impurity phases it is necessary to have information about their properties. However, these ferrites are investigated insufficiently. It should be noted that the study of magnetic, electrical and other properties of the ferrite Bi2Fe4O9, which is a good catalyst and the n Correspondence to: Physical and Colloidal Chemistry Department, Belarussian State Technological University, Sverdlova Street, 13a, 220050 Minsk, Belarus. Tel.: þ 375 29 216 38 66; fax: þ 375 8 017 327 62 17. E-mail address: [email protected] (A.A. Zatsiupa).
http://dx.doi.org/10.1016/j.jssc.2014.01.019 0022-4596 & 2014 Elsevier Inc. All rights reserved.
material for the making of gas sensors, is the subject of several papers [17–20], but the data on the magnetic properties of ferrite Bi25FeO39 are given only in [21], where at 10 K the ferromagnetic state is found, although many authors consider that there is no magnetic ordering in Bi25FeO39. In this regard, the purpose of this paper is to study at 5 950 K magnetic susceptibility, as well as magnetization at 5 K in fields up to 10 T for Bi25FeO39 ferrite and evaluation of the effective magnetic moment of Fe3 þ ions in this compound.
2. Experimental procedure Synthesis of the sample Bi25FeO39 is carried out by solid-state reactions method from the Bi2O3 and Fe2O3 oxides. Powders of the starting substance, taken in prescribed molar ratios, were mixed and milled for 30 min in a planetary mill “Pulverizette 6” with the addition of ethanol. The resulting mixture with ethanol addition was compressed under the 50 75 MPa pressure into pellets with 25 mm diameter and 5 7 mm height and then was calcined at 1073 K in air for 4 h. After calcination pellets were crushed, milled, pressed into rods, having 30 mm long and 5 5 mm2 section, and annealed at of 1073 K in air for 4 h. X-ray diffractograms were obtained by a D8 ADVANCE diffractometer using CuKα-radiation. The parameters of the Bi25FeO39 crystal lattice were determined by X-ray table processor RTP and
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A.A. Zatsiupa et al. / Journal of Solid State Chemistry 212 (2014) 147–150
Fig. 1. X-ray diffraction pattern of Bi25FeO39 ferrite.
Fig. 2. The temperature dependence of the specific magnetization for the compounds Bi25FeO39 in the temperature ranges 5 300 K (a) and 77 950 K (b).
data filing of International Center for Diffraction Data (ICDD JCPDS). The specific magnetization (s) of Bi25FeO39 at 5 K in fields (H) up to 10 T and magnetic susceptibility (χ) in a magnetic field of 0.86 T in the 5 300 K temperature range was measured at the Scientific and Practical Materials Research Centre of the NAS of Belarus by vibration method using a universal high-field measuring system (Cryogenic Ltd., London) and by Faraday method in the temperature range 77 950 K.
3. Results and discussion X-ray analysis (Fig. 1) showed that the bismuth ferrite Bi25FeO39 was single phase and had a cubic crystal structure of sillenite (sp. gr. I23) with the crystal lattice parameters of a¼ 10.1730 Å, V¼ 1052.810 Å3, which are in a good agreement with literature data (a¼ 10.18120 Å and V¼1055.350 Å3) [22]. Temperature dependences of specific magnetization (s) for Bi25FeO39, obtained in a 0.86 T magnetic field by vibration method in the temperature range 5 300 K (Fig. 2a) and by Faraday method in the temperature range 77 950 K (Fig. 2b), were in a good agreement. The curves s ¼ f(T) at heating and cooling were coincided in the temperature range 300 950 K (Fig. 2b).
Fig. 3. The dependence of the magnetization (n, μB) on the magnetic field for one formula unit of Bi25FeO39 at 5 K.
The dependence of the magnetization (n, μB) of Bi25FeO39 one formula unit on the magnetic field at 5 K is linear in fields up to 1 T (Fig. 3), while at higher fields, it gradually reached to a constant value, and in a field of 10 T it was equal to 5.04μB, which
A.A. Zatsiupa et al. / Journal of Solid State Chemistry 212 (2014) 147–150
149
Fig. 4. Temperature dependence of molar magnetic susceptibility (χmol) (curve 1) and the reciprocal molar magnetic susceptibility (1/χmol) (curve 2) for Bi25FeO39 in the temperature ranges 5 300 K (a) and 77 800 K (b).
practically coincided with the magnetic moment of the Fe3 þ ion in the high-spin state (μFe3 þ ¼ 5:0μB ). It should be noted that the saturation magnetization (ns, μB) for Bi25FeO39 occurred at H/T ¼20 kOe/K, and for the paramagnetic iron ammonium alum NH4Fe(SO4)2 12H2O saturation magnetization (ns ¼5μB) is reached at 1.3 K in a magnetic field of 52 kOe (Н/Т ¼40 kOe/K) [23]. It is important to emphasize that for Bi25FeO39 on the field dependence of the magnetization with increasing and decreasing magnetic field at 5 K, there was no hysteresis loop (Fig. 3, inset). So our results differ from those of [21], where for Bi25FeO39, prepared by the hydrothermal method in an alkaline medium (KOH), on the magnetization curve at 10 K in fields not higher than 500 Oe, the hysteresis loop is observed (Hc ¼287 Oe). This difference of our results and data of [21] is fundamental, because in several studies (see [15]), the presence of weak ferromagnetism in the BiFeO3 ferrite is associated with the presence of impurity Bi25FeO39 phase, which was considered as a weak ferromagnet. However, our data on the field dependence of magnetization (Fig. 3) and the temperature dependence of magnetic susceptibility for ferrite Bi25FeO39 show that Bi25FeO39 is paramagnetic in the temperature range 5 950 K. The experimentally obtained temperature dependences of the molar magnetic susceptibility (χmol, cm3/mol) and the reciprocal molar magnetic susceptibility (1/χmol, mol/cm3) for Bi25FeO39 in the temperature range 5 300 K and 77 950 K are shown in Fig. 4a and b respectively. It is seen that the dependence of 1/χmol on T for Bi25FeO39 in the temperature range 5 300 K (Fig. 4, curve 2) is linear, indicating that the implementation of the Curie Weiss law takes place. According to the Curie Weiss law the temperature dependence of the molar magnetic susceptibility is described by the following equation:
χ mol ¼
СM
pffiffiffiffiffiffiffi
μeff ;Fe3 þ ¼ 2:828 C M ;
ð2Þ qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 2 where 2:828 ¼ 3kB =NA μB ; kB is Boltzmann constant; NA is Avogadro number; and μB is the Bohr magneton. It is found that the effective magnetic moment of Fe3 þ ions (μeff ;Fe3 þ ) in the ferrite Bi25FeO39 is 5.82μB. This value for the Bi25FeO39 differs only slightly from the theoretical value of the effective magnetic moment of free Fe3 þ ions, which are in a highspin state (μeff ;Fe3 þ ¼ 5:92μB ). This fact also indicates a lack of any HS magnetic ordering (ferro-, ferri- or antiferromagnetic) in Bi25FeO39 in the temperature range 5 300 K.
4. Conclusion The data on the field dependence of magnetization at 5 K and the temperature dependence of magnetic susceptibility for Bi25FeO39 ferrite show that in the temperature range 5 950 K Bi25FeO39 is paramagnetic and at 5 K on the curve of magnetization hysteresis loop is not observed. The saturation magnetization of one formula unit of Bi25FeO39 at 5 K is reached in the field of 10 T and it is equal to 5.04μB. It is found that the effective magnetic moment of Fe3 þ ions in Bi25FeO39 is 5.82μB, which is only 0.1μB smaller than effective magnetic moment of Fe3 þ ions in high-spin state (μeff ;Fe3 þ ;HS ¼ 5:92μB ). References [1] [2] [3] [4]
ð1Þ
[5]
where СM is a molar Curie constant and Θ is a Weiss constant (paramagnetic Curie temperature). In the temperature range 400 800 K the 1/χmol on T dependence for Bi25FeO39 is not linear (Fig. 4b, curve 2) and the Curie Weiss law is not realized. For the temperature range 5 300 K by the least squares method we obtained an equation of the linear dependence of 1/χmol on T (1/χmol ¼ а þbT). Using the coefficients a and b, values of the molar Curie constant (CM ¼4.24 cm3 K/mol) and the Weiss constant (Θ ¼3.6 K) were calculated. The effective magnetic moment of the Fe3 þ ions (μeff ; Fe3 þ ) in the temperature range of implementation of the Curie Weiss law was calculated for Bi25FeO39 by the following
[6] [7] [8]
T Θ
;
formula:
[9] [10] [11] [12] [13] [14] [15] [16]
A. Maitre, M. Francois, J.C. Gachon, J. Phase Equilibria Diffusion 25 (2004) 59. G. Catalan, J.F. Scott, Adv. Mater. 21 (2009) 2463. T.T. Carvalho, P.B. Tavares, Mater. Lett. 62 (2008) 3984. M.S. Bernardo, T. Jardiel, M. Peiteado, A.C. Caballero, M. Villegas, J. Eur. Ceram. Soc. 31 (2011) 3047. M.I. Morozov, N.A. Lomanova, V.V. Gusarov, Russ. J. Gen. Chem. 73 (2003) 1772. A.K. Zvezdin, A.P. Pyatakov, Phys. Usp. 47 (2004) 416. G.A. Smolensky, V.M. Yudin, E.S. SherYu.E. Stolypin, JETP 43 (1962) 877. C. Michel, J.M. Moreau, G.B. Achenbach, R. Gerson, W.J. James, Solid State Commun. 7 (1969) 701. I.O. Troyanchuk, M.V. Bushinsky, A.N. Chobot, O.S. Mantytskaya, N.V. Tereshko, JETP Lett. 89 (2009) 204. I.O. Troyanchuk, D.V. Karpinsky, M.V. Bushinsky, O.S. Mantytskaya, N.V. Tereshko, V.N. Shut, J. Am. Ceram. Soc. 94 (2011) 4502. Y. Hu, L. Fei, Y. Zhang, et al., J. Nanomater. (2011) 1. D. Kan, L. Palova, V. Anbusathaiah, Adv. Funct. Mater. 20 (2010) 1108. X. He, L. Gao, Ceram. Int. 35 (2009) 975. S.M. Selbach, T. Tybell, M.-A. Einarsrud, T. Grande, J. Solid State Chem. 183 (2010) 1205. D. Lebeugle, D. Colson, A. Forget, M. Viret, P. Bonville, J.F. Marucco, S. Fusil, Phys. Rev. B 76 (2007) 024116. S.K. Pradhan, B.K. Roul, J. Phys. Chem. Solids 72 (2011) 1180.
150
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[17] E. Ressourche, V. Simonet, B. Canals, M. Gospodinov, V. Skumryev, Phys. Rev. Lett. 103 (2009) 267204. [18] J.T. Han, Y.H. Huang, R.J. Jia, G.C. Shan, R.Q. Guo, W. Huang, J. Cryst. Growth 294 (2006) 469. [19] Y. Wang, G. Xu, L. Yang, Z. Ren, X. Wei, W. Weng, et al., Cer. Int. 35 (2009) 51. [20] Y. Du, Z.X. Cheng, S.X. Dou, X.L. Wang, Mater. Lett. 64 (2010) 2251. [21] Du Y. Multiferroic transition metal oxides: structural, magnetic, ferroelectric and thermal properties, Doctor of Philosophy thesis, University of
Wollongong. Institute for Superconducting & Electronic Materials [Electronic resource], Mode of access: 〈http://ro.uow.edu.au/theses/3247〉, 2011 (acessed 22.03.12). [22] Powder diffraction file. Swarthmore: Joint Committee on Powder Diffraction Standard: Card No. 00-046-0416. [23] G.S. Krinchik, Fizika Magnitnykh Yavlenii, The Physics of Magnetism, Mosc. Gos. Univ., Moscow, 1976.
Contents lists available at ScienceDirect
Journal of Solid State Chemistry journal homepage: www.elsevier.com/locate/jssc
Magnetization, magnetic susceptibility, effective magnetic moment of Fe3 þ ions in Bi25FeO39 ferrite A.A. Zatsiupa a,n, L.A. Bashkirov a, I.O. Troyanchuk b, G.S. Petrov a, A.I. Galyas b, L.S. Lobanovsky b, S.V. Truhanov b a b
Belarussian State Technological University, 220030 Minsk, Belarus Scientific and Practical Materials Research Centre of the NAS of Belarus, 220072 Minsk, Belarus
art ic l e i nf o
a b s t r a c t
Article history: Received 20 April 2013 Received in revised form 13 January 2014 Accepted 15 January 2014 Available online 1 February 2014
Magnetic susceptibility for ferrite Bi25FeO39 is measured at 5–950 K in the magnetic field of 0.86 T. It is shown that Bi25FeO39 is paramagnetic in the temperature range 5 950 K. The saturation magnetization is equal to 5.04μB per formula unit at 5 K in a magnetic field of 10 T. It is found that at 5 300 K the effective magnetic moment of Fe3 þ ions in Bi25FeO39 is equal to 5.82μB. & 2014 Elsevier Inc. All rights reserved.
Keywords: Ceramics Crystal structure Magnetic susceptibility Effective magnetic moment of Fe3 þ Ferrite
1. Introduction It is known [1–5] that during interaction of bismuth oxide Bi2O3 with iron oxide Fe2O3 three compounds may be formed: Bi25FeO39, BiFeO3 and Bi2Fe4O9. Of these, bismuth ferrite BiFeO3 with the structure of rhombohedrally distorted perovskite is multiferroics, in which up to the Neel temperature (TN ¼643 K) at the same time there is an antiferromagnetic ordering of magnetic moments of Fe3 þ ions as well as the ordering of electric dipoles at temperatures below the Curie temperature (TC ¼1083 K) [6–8]. To date, many papers are published concerning the development of methods of preparation and study the properties of bismuth ferrite BiFeO3 and solid solutions based on it [4,9–16]. It is found that by means of solid-state reactions, the sol–gel and other methods, it is difficult to prepare single-phase samples of BiFeO3, and in most cases they contain a small amount of impurity phases of Bi25FeO39 and Bi2Fe4O9 ferrite, the presence of which distorts the results obtained. To take into account the effect of these impurity phases it is necessary to have information about their properties. However, these ferrites are investigated insufficiently. It should be noted that the study of magnetic, electrical and other properties of the ferrite Bi2Fe4O9, which is a good catalyst and the n Correspondence to: Physical and Colloidal Chemistry Department, Belarussian State Technological University, Sverdlova Street, 13a, 220050 Minsk, Belarus. Tel.: þ 375 29 216 38 66; fax: þ 375 8 017 327 62 17. E-mail address: [email protected] (A.A. Zatsiupa).
http://dx.doi.org/10.1016/j.jssc.2014.01.019 0022-4596 & 2014 Elsevier Inc. All rights reserved.
material for the making of gas sensors, is the subject of several papers [17–20], but the data on the magnetic properties of ferrite Bi25FeO39 are given only in [21], where at 10 K the ferromagnetic state is found, although many authors consider that there is no magnetic ordering in Bi25FeO39. In this regard, the purpose of this paper is to study at 5 950 K magnetic susceptibility, as well as magnetization at 5 K in fields up to 10 T for Bi25FeO39 ferrite and evaluation of the effective magnetic moment of Fe3 þ ions in this compound.
2. Experimental procedure Synthesis of the sample Bi25FeO39 is carried out by solid-state reactions method from the Bi2O3 and Fe2O3 oxides. Powders of the starting substance, taken in prescribed molar ratios, were mixed and milled for 30 min in a planetary mill “Pulverizette 6” with the addition of ethanol. The resulting mixture with ethanol addition was compressed under the 50 75 MPa pressure into pellets with 25 mm diameter and 5 7 mm height and then was calcined at 1073 K in air for 4 h. After calcination pellets were crushed, milled, pressed into rods, having 30 mm long and 5 5 mm2 section, and annealed at of 1073 K in air for 4 h. X-ray diffractograms were obtained by a D8 ADVANCE diffractometer using CuKα-radiation. The parameters of the Bi25FeO39 crystal lattice were determined by X-ray table processor RTP and
148
A.A. Zatsiupa et al. / Journal of Solid State Chemistry 212 (2014) 147–150
Fig. 1. X-ray diffraction pattern of Bi25FeO39 ferrite.
Fig. 2. The temperature dependence of the specific magnetization for the compounds Bi25FeO39 in the temperature ranges 5 300 K (a) and 77 950 K (b).
data filing of International Center for Diffraction Data (ICDD JCPDS). The specific magnetization (s) of Bi25FeO39 at 5 K in fields (H) up to 10 T and magnetic susceptibility (χ) in a magnetic field of 0.86 T in the 5 300 K temperature range was measured at the Scientific and Practical Materials Research Centre of the NAS of Belarus by vibration method using a universal high-field measuring system (Cryogenic Ltd., London) and by Faraday method in the temperature range 77 950 K.
3. Results and discussion X-ray analysis (Fig. 1) showed that the bismuth ferrite Bi25FeO39 was single phase and had a cubic crystal structure of sillenite (sp. gr. I23) with the crystal lattice parameters of a¼ 10.1730 Å, V¼ 1052.810 Å3, which are in a good agreement with literature data (a¼ 10.18120 Å and V¼1055.350 Å3) [22]. Temperature dependences of specific magnetization (s) for Bi25FeO39, obtained in a 0.86 T magnetic field by vibration method in the temperature range 5 300 K (Fig. 2a) and by Faraday method in the temperature range 77 950 K (Fig. 2b), were in a good agreement. The curves s ¼ f(T) at heating and cooling were coincided in the temperature range 300 950 K (Fig. 2b).
Fig. 3. The dependence of the magnetization (n, μB) on the magnetic field for one formula unit of Bi25FeO39 at 5 K.
The dependence of the magnetization (n, μB) of Bi25FeO39 one formula unit on the magnetic field at 5 K is linear in fields up to 1 T (Fig. 3), while at higher fields, it gradually reached to a constant value, and in a field of 10 T it was equal to 5.04μB, which
A.A. Zatsiupa et al. / Journal of Solid State Chemistry 212 (2014) 147–150
149
Fig. 4. Temperature dependence of molar magnetic susceptibility (χmol) (curve 1) and the reciprocal molar magnetic susceptibility (1/χmol) (curve 2) for Bi25FeO39 in the temperature ranges 5 300 K (a) and 77 800 K (b).
practically coincided with the magnetic moment of the Fe3 þ ion in the high-spin state (μFe3 þ ¼ 5:0μB ). It should be noted that the saturation magnetization (ns, μB) for Bi25FeO39 occurred at H/T ¼20 kOe/K, and for the paramagnetic iron ammonium alum NH4Fe(SO4)2 12H2O saturation magnetization (ns ¼5μB) is reached at 1.3 K in a magnetic field of 52 kOe (Н/Т ¼40 kOe/K) [23]. It is important to emphasize that for Bi25FeO39 on the field dependence of the magnetization with increasing and decreasing magnetic field at 5 K, there was no hysteresis loop (Fig. 3, inset). So our results differ from those of [21], where for Bi25FeO39, prepared by the hydrothermal method in an alkaline medium (KOH), on the magnetization curve at 10 K in fields not higher than 500 Oe, the hysteresis loop is observed (Hc ¼287 Oe). This difference of our results and data of [21] is fundamental, because in several studies (see [15]), the presence of weak ferromagnetism in the BiFeO3 ferrite is associated with the presence of impurity Bi25FeO39 phase, which was considered as a weak ferromagnet. However, our data on the field dependence of magnetization (Fig. 3) and the temperature dependence of magnetic susceptibility for ferrite Bi25FeO39 show that Bi25FeO39 is paramagnetic in the temperature range 5 950 K. The experimentally obtained temperature dependences of the molar magnetic susceptibility (χmol, cm3/mol) and the reciprocal molar magnetic susceptibility (1/χmol, mol/cm3) for Bi25FeO39 in the temperature range 5 300 K and 77 950 K are shown in Fig. 4a and b respectively. It is seen that the dependence of 1/χmol on T for Bi25FeO39 in the temperature range 5 300 K (Fig. 4, curve 2) is linear, indicating that the implementation of the Curie Weiss law takes place. According to the Curie Weiss law the temperature dependence of the molar magnetic susceptibility is described by the following equation:
χ mol ¼
СM
pffiffiffiffiffiffiffi
μeff ;Fe3 þ ¼ 2:828 C M ;
ð2Þ qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 2 where 2:828 ¼ 3kB =NA μB ; kB is Boltzmann constant; NA is Avogadro number; and μB is the Bohr magneton. It is found that the effective magnetic moment of Fe3 þ ions (μeff ;Fe3 þ ) in the ferrite Bi25FeO39 is 5.82μB. This value for the Bi25FeO39 differs only slightly from the theoretical value of the effective magnetic moment of free Fe3 þ ions, which are in a highspin state (μeff ;Fe3 þ ¼ 5:92μB ). This fact also indicates a lack of any HS magnetic ordering (ferro-, ferri- or antiferromagnetic) in Bi25FeO39 in the temperature range 5 300 K.
4. Conclusion The data on the field dependence of magnetization at 5 K and the temperature dependence of magnetic susceptibility for Bi25FeO39 ferrite show that in the temperature range 5 950 K Bi25FeO39 is paramagnetic and at 5 K on the curve of magnetization hysteresis loop is not observed. The saturation magnetization of one formula unit of Bi25FeO39 at 5 K is reached in the field of 10 T and it is equal to 5.04μB. It is found that the effective magnetic moment of Fe3 þ ions in Bi25FeO39 is 5.82μB, which is only 0.1μB smaller than effective magnetic moment of Fe3 þ ions in high-spin state (μeff ;Fe3 þ ;HS ¼ 5:92μB ). References [1] [2] [3] [4]
ð1Þ
[5]
where СM is a molar Curie constant and Θ is a Weiss constant (paramagnetic Curie temperature). In the temperature range 400 800 K the 1/χmol on T dependence for Bi25FeO39 is not linear (Fig. 4b, curve 2) and the Curie Weiss law is not realized. For the temperature range 5 300 K by the least squares method we obtained an equation of the linear dependence of 1/χmol on T (1/χmol ¼ а þbT). Using the coefficients a and b, values of the molar Curie constant (CM ¼4.24 cm3 K/mol) and the Weiss constant (Θ ¼3.6 K) were calculated. The effective magnetic moment of the Fe3 þ ions (μeff ; Fe3 þ ) in the temperature range of implementation of the Curie Weiss law was calculated for Bi25FeO39 by the following
[6] [7] [8]
T Θ
;
formula:
[9] [10] [11] [12] [13] [14] [15] [16]
A. Maitre, M. Francois, J.C. Gachon, J. Phase Equilibria Diffusion 25 (2004) 59. G. Catalan, J.F. Scott, Adv. Mater. 21 (2009) 2463. T.T. Carvalho, P.B. Tavares, Mater. Lett. 62 (2008) 3984. M.S. Bernardo, T. Jardiel, M. Peiteado, A.C. Caballero, M. Villegas, J. Eur. Ceram. Soc. 31 (2011) 3047. M.I. Morozov, N.A. Lomanova, V.V. Gusarov, Russ. J. Gen. Chem. 73 (2003) 1772. A.K. Zvezdin, A.P. Pyatakov, Phys. Usp. 47 (2004) 416. G.A. Smolensky, V.M. Yudin, E.S. SherYu.E. Stolypin, JETP 43 (1962) 877. C. Michel, J.M. Moreau, G.B. Achenbach, R. Gerson, W.J. James, Solid State Commun. 7 (1969) 701. I.O. Troyanchuk, M.V. Bushinsky, A.N. Chobot, O.S. Mantytskaya, N.V. Tereshko, JETP Lett. 89 (2009) 204. I.O. Troyanchuk, D.V. Karpinsky, M.V. Bushinsky, O.S. Mantytskaya, N.V. Tereshko, V.N. Shut, J. Am. Ceram. Soc. 94 (2011) 4502. Y. Hu, L. Fei, Y. Zhang, et al., J. Nanomater. (2011) 1. D. Kan, L. Palova, V. Anbusathaiah, Adv. Funct. Mater. 20 (2010) 1108. X. He, L. Gao, Ceram. Int. 35 (2009) 975. S.M. Selbach, T. Tybell, M.-A. Einarsrud, T. Grande, J. Solid State Chem. 183 (2010) 1205. D. Lebeugle, D. Colson, A. Forget, M. Viret, P. Bonville, J.F. Marucco, S. Fusil, Phys. Rev. B 76 (2007) 024116. S.K. Pradhan, B.K. Roul, J. Phys. Chem. Solids 72 (2011) 1180.
150
A.A. Zatsiupa et al. / Journal of Solid State Chemistry 212 (2014) 147–150
[17] E. Ressourche, V. Simonet, B. Canals, M. Gospodinov, V. Skumryev, Phys. Rev. Lett. 103 (2009) 267204. [18] J.T. Han, Y.H. Huang, R.J. Jia, G.C. Shan, R.Q. Guo, W. Huang, J. Cryst. Growth 294 (2006) 469. [19] Y. Wang, G. Xu, L. Yang, Z. Ren, X. Wei, W. Weng, et al., Cer. Int. 35 (2009) 51. [20] Y. Du, Z.X. Cheng, S.X. Dou, X.L. Wang, Mater. Lett. 64 (2010) 2251. [21] Du Y. Multiferroic transition metal oxides: structural, magnetic, ferroelectric and thermal properties, Doctor of Philosophy thesis, University of
Wollongong. Institute for Superconducting & Electronic Materials [Electronic resource], Mode of access: 〈http://ro.uow.edu.au/theses/3247〉, 2011 (acessed 22.03.12). [22] Powder diffraction file. Swarthmore: Joint Committee on Powder Diffraction Standard: Card No. 00-046-0416. [23] G.S. Krinchik, Fizika Magnitnykh Yavlenii, The Physics of Magnetism, Mosc. Gos. Univ., Moscow, 1976.