Influence of gadolinium and dysprosium substitution on magnetic properties and magnetocaloric effect of Fe78−xRExSi4Nb5B12Cu1 amorphous alloys

Journal Pre-proof Influence of gadolinium and dysprosium substitution on magnetic properties and magnetocaloric effect of Fe78−xRExSi4Nb5B12Cu1 amorphous alloys Lizhong Zhao, Huachun Tian, Xichun Zhong, Zhongwu Liu, Jean-Marc Greneche, R.V. Ramanujan PII:

S1002-0721(19)30752-5

DOI:

https://doi.org/10.1016/j.jre.2020.02.005

Reference:

JRE 706

To appear in:

Journal of Rare Earths

Received Date: 10 September 2019 Revised Date:

12 December 2019

Accepted Date: 12 February 2020

Please cite this article as: Zhao L, Tian H, Zhong X, Liu Z, Greneche JM, Ramanujan RV, Influence of gadolinium and dysprosium substitution on magnetic properties and magnetocaloric effect of Fe78−xRExSi4Nb5B12Cu1 amorphous alloys, Journal of Rare Earths, https://doi.org/10.1016/ j.jre.2020.02.005. This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. © 2020 Published by Elsevier B.V. on behalf of Chinese Society of Rare Earths.

Influence of gadolinium and dysprosium substitution on magnetic properties and magnetocaloric effect of Fe78−xRExSi4Nb5B12Cu1 amorphous alloys Lizhong Zhaoa, Huachun Tianb,c, Xichun Zhongb, *, Zhongwu Liub, Jean-Marc Greneched, R.V. Ramanujane,f1 a. Institute of Advanced Magnetic Materials, Hangzhou Dianzi University, Hangzhou 310012, China. b. School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China. c. Guangdong Institute of Special Equipment Inspection and Research, Guangzhou 528251, China. d. Institut des Molécules et Matériaux du Mans UMR CNRS 6283, Le Mans Université, Avenue Messiaen, Le Mans F-72085, France. e. School of Materials Science and Engineering, Nanyang Technological University, 639798, Singapore. f. Singapore-HUJ Alliance for Research and Enterprise (SHARE), Nanomaterials for Energy and Energy-Water Nexus (NEW), Campus for Research Excellence and Technological Enterprise (CREATE), Singapore 138602, Singapore.

Abstract: Amorphous Fe78−xRExSi4Nb5B12Cu1 (RE=Gd, Dy) ribbons with different RE contents were prepared by melt spinning to investigate the effect of heavy rare earth (Gd, Dy) substitution on the hyperfine structure, magnetic properties and magnetocaloric effect. The Curie temperature of RE substituted alloys, hyperfine field and magnetic moments of Fe atoms initially increase up to 1% RE content and then decrease monotonously for increasing RE content up to 10%. The dependence of magnetic entropy change (–∆SM) and refrigeration capacity (RC) of the alloys on RE contents displays the same tendency. The RCAREA values of the alloys substituted with 1 at% Gd and Dy are similar to those of recently reported Fe-based metallic glasses with enhanced RC values compared to those of Gd5Ge1.9Si2Fe0.1. Enhanced (–∆SM) and RC values, negligible coercive force and Foundation items: Project supported by the National Natural Science Foundation of China (51874143, 51801047), the Natural Science Foundation of Guangdong Province (2017A030313317) and Natural Science Foundation of Zhejiang Province (LY20E010002)

* Corresponding authors: Prof. X.C. Zhong (E-mail: [email protected]; Tel.: +86-2087111312)

hysteresis commonly make these Fe78−xRExSi4Nb5B12Cu1 amorphous alloys as low-cost candidates for high-temperature magnetic refrigeration. Keywords: Magnetic properties; Magnetocaloric effect; Refrigeration capacity; Rare earths

1 Introduction Since magnetocaloric effect (MCE) was found by Warburg in 1881 [1], the magnetocaloric materials (MCMs) have been developed for more than 130 years. As a new type of refrigeration technology, room temperature magnetic refrigeration based on the MCE has attracted considerable attention due to its advantages for highly efficient, energy saving and environment friendly [2-5]. A well-established milestone in room temperature magnetic refrigeration is the development of magnetic refrigeration wine cabinet without a compressor, which is fabricated by Haier, BASF and Astronautics corporation [6, 7]. With the maturing of magnetic refrigerator, the MCMs have started a way to the commercial application. Therefore, the price of raw materials has become a critical factor in material selection. Fe-based amorphous materials with less expensive elements have shown potential applications. In addition, tunable Curie temperature (TC), small thermal and/or magnetic hysteresis, broad magnetic entropy change peak, and high electronic resistivity make them be competitive MCMs for practical application. Among Fe-based amorphous alloys, NANOPERM type alloy displays the highest MCE, but usually at elevated temperatures [8-10]. Franco et al. investigated the influence of light rare earth (LRE, e.g., La, Ce) and heavy rare earth (HRE, e.g., Gd) addition on the magnetic and magnetocaloric properties of the Fe-B-Cr amorphous alloys [11, 12]. The results showed that Fe80−xGdxB12Cr8 alloys substituted with 1 at% Gd exhibited enhanced peak value of magnetic entropy change (–∆SMpk) (~33% larger than that of Fe80B12Cr8 at%) and refrigeration capacity (RCAREA) (~29% larger than that of Gd5Si2Ge1.9Fe0.1 at% [13]). They attributed the enhanced –∆SMpk to the ferromagnetic coupling between Fe and Cr moments [14]. Li et al. studied the MCE in HRE elements (e.g., Gd, Dy, Ho) substituted Fe-Nb-B-based bulk metallic glasses [15]. These results showed that the TC could be adjusted in a large temperature range of 120 K by varying HRE and their contents. However, the –∆SMpk decreases with increasing Dy content. In our previous work [16], Ce substituted Fe-Si-Nb-B-Cu alloys have varied TC

from 348 to 281 K. In the present work, the effect of Gd or Dy substitution for Fe on the magnetic and magnetocaloric properties of Fe78−xRExSi4Nb5B12Cu1 at% (RE=Gd and Dy) amorphous alloys were investigated in detail and the comparison between the heavy rare earth (Gd, Dy) and light rare earth (Ce) substituted alloys were carried out. 2 Experimental Buttons of nominal compositions (in at%) Fe78−xRExSi4Nb5B12Cu1 (RE=Gd, Dy; x=0, 1, 3, 5, 10) were prepared by arc-melting pure Fe, FeB (≥99.95 wt%) and Gd, Dy, Si, Nb, B, Cu (≥99.8 wt%) in argon atmosphere. To ensure the composition homogeneity, the ingots were re-melted 5 times. The ingots were subsequently melt-spun into ribbons with thickness of ~20 µm and width of ~1 mm by single-roller melt spinner at a wheel speed of 50 m/s in argon atmosphere. The ribbons with Gd and Dy substitution are denoted by their RE contents as Gd1, Gd3, Gd5, Gd10 and Dy1, Dy3, Dy5, Dy10, respectively. The structures of the meltspun ribbons were characterized by the PANalytical X-ray diffractometer (XRD) with Cu Kα radiation at room temperature. Magnetic measurements were carried out using Quantum Design physical property measurement system (PPMS-9). The hyperfine structure of the alloys was investigated by 57Fe Mössbauer spectrometry (MS), and the spectra were recorded at 300 K in a transmission geometry using 57Co/Rh γ-ray source. 3 Results and discussion Fig.1 displays the XRD patterns of as-spun Fe78−xRExSi4Nb5B12Cu1 (RE=Gd, Dy) alloys. Only a broad diffraction peak without any detectable sharp Bragg peak of each alloy was observed, indicating the fully amorphous structure.

Fig.1 here

Fig. 2 compares the Mössbauer spectra of the Dy-substituted alloys at 300 K while the corresponding refined values of hyperfine parameters are listed in Table 1. All the spectra are fitted by means of discrete distribution of hyperfine fields, while the values of isomer shift and quadrupolar shift are commonly refined, the line width being fixed. The value of angle θ defined by the direction of hyperfine field and γ-ray was set free but commonly refined. For some samples, the texture-free spectrum was recorded using the magic angle configuration to prevent from some misfits in the estimation of the mean angle and the distribution of hyperfine field [16, 17]. The corresponding distributions of the hyperfine field are compared in Fig. 3. They depict the typical behavior of the amorphous phase, which confirms thus the amorphous structure of those Dy-substituted

alloys [18]. The refined mean hyperfine field at the Fe atoms are 20.0, 22.5, 20.1, 20.3, 17.4 (±0.5) T for the Dy0, Dy1, Dy3, Dy5, Dy10 alloys, respectively. It first increases with increasing Dy content, peaks at Dy1, and then decreases. Since the hyperfine field is determined by the strength of the magnetic coupling between the Fe atoms, hence, one can imagine that the magnetic properties show a similar change. By using the rule of 15T/µB, the mean moments of Fe atoms can be calculated as 1.33, 1.43, 1.34, 1.35, and, 1.16 (±0.05) µB [19].

Fig.2 here Fig.3 here TABLE 1 here

The temperature dependences of magnetization and magnetic susceptibility (χ) for Fe77Gd1Si4Nb5B12Cu1 alloy are displayed as an example in Fig. 4. The Curie temperature (TC) and the paramagnetic point ( p ) are determined as 548 and 534 K, respectively. It is clear that the χ–T obeys Curie-Weiss law very well in the temperature range above TC. By using the same rule, all the TC values of the Gd- and Dy-substituted alloys are determined and listed in Table II. For the Dy-substituted alloys, the change of TC is similar to the tendency of hyperfine field as a function of Dy content. That is, it increases first and peaks at 512 K for Dy1, and then decreases with increasing the substitution content. A similar change trend is also observed for the Gd-substituted alloys except for Gd10 alloy. The concrete reason will be discussed below.

Fig. 4. here TABLE 2 HERE

The total magnetic entropy change of the system under a magnetic field can be derived from Maxwell relation by integrating over the magnetic field [20]: ∆

,

=

,

−

,0 =



Eq. (1)

where H represents the highest value of magnetic field. The temperature dependences of magnetic entropy changes of the Fe78−xRExSi4Nb5B12Cu1 (RE=Gd, Dy; x=0, 1, 3, 5, 10) alloys under an applied field change of 1.5 T are presented in Fig 5. The peak values of −∆SM for Gd1, Gd3, Gd5, Gd10 and Dy1, Dy3, Dy5, Dy10 are 1.66, 1.45, 1.1, 0.97 and 1.74, 1.51, 1.56,

1.0 J/(kg‧K), respectively. The variation of |∆S Mpk | and TC value with heavy Dy substitution shows a similar change with the hyperfine field of Fe for all alloys. Thus, it could be concluded that the ferromagnetism of the Dy-substituted alloys are mainly originated from the coupling of Fe atoms, as well as the Gd-substituted amorphous alloys with the similar composition and phase structure. The similar results were observed in the Gd-substituted alloys. When x=1, the –∆SMpk value of Dy-substituted alloy was 1.74 J/(kg‧K), larger than that of Nanoperm type alloy Fe88Zr7B4Cu1 at%, which exhibits the largest RC value in Fe-based amorphous alloy. The values of TC, Tpk, –∆SMpk, and RC AREA for RE content dependent Fe78–xRExSi4Nb5B12Cu1 (RE=Gd, Dy) amorphous alloys under an applied field change of 1.5 T are listed in Table 2. For comparison, those values of the Fe78– xCexSi4Nb5B12Cu1 alloys are also supplied. The results show clearly a monotonous decrease of TC with increasing Ce content in Ce-substituted alloys. On the contrary, a small amount of heavy RE (RE=Gd, Dy) substitution for part of Fe favors an increase of TC, but the further increase of RE content could lower TC by decreasing the exchange coupling between Fe-Fe atoms. However, when Gd/Dy (x=10) atoms replace Fe atoms, the Gd-Fe/Dy-Fe interchange is weakened, and the couplings of Fe–Fe and Gd-Gd/Dy-Dy play a dominate role [14, 21, 22], resulting in an abnormal increase of TC.

Fig.5. here

The Dy contents dependent −∆SMpk, µFe and TC are plotted in Fig. 6. It has been well established that the µFe and TC are strongly dependent on the ferromagnetic coupling of the alloy and the magnetic entropy change values has a deep correlation with the magnetic moment [23-25]. That is why −∆SMpk, µFe and TC all show the similar tendency with the increasing Dy content, initially increased with the increasing RE content up to 1 at% then followed an approximately monotonic decrease.

Fig.6. here

Currently, a reference standard to evaluate refrigeration efficiency is refrigerant capacity (RC), which is defined as the heat transferred between the hot and cold reservoirs used in a thermodynamic cycle [26]. It is a comprehensive parameter depending on the numerical integration of the area under the (−∆SM)–T curves, using the full temperature width at half maximum of the peak as the integration limits.

=

!"

|Δ

|d

Eq. (2)

Under an applied field change of 1.5T, the RCAREA values for Gd1, Gd3, Gd5, Gd10 and Dy1, Dy3, Dy5, Dy10 are 90, 77, 69, 46 and 93, 78, 83, 46 J/kg, respectively. Comparing to the RCAREA value of 89 J/kg for Fe78Si4Nb5B12Cu1 at% amorphous alloy without RE addition, the RCAREA value exhibits a small increase with 1 at% RE substitution and then decreases when the amount of RE substitution increases, which are similar to the tendency of the RE content dependence of magnetic entropy change. The RCAREA values of the studied alloys substituted RE are comparable and even larger than those of Fe80−xB12Cr8Gdx at% amorphous alloys with the same amount of Gd additions [12]. 4 Conclusions The study of the effect of heavy rare-earth (Gd and Dy) addition on the magnetic properties and magnetocaloric effect of Fe78−xRExSi4Nb5B12Cu1 at% amorphous allows thus to distinguish three main features: (1) the substitution of 1% Gd and Dy for Fe in Fe78−xRExSi4Nb5B12Cu1 alloys results in the enhancement of TC, –∆SMpk, and µFe, which is not observed in the case of 1% Ce; (2) the Curie temperature of Gd and Dy substituted alloys which initially increases up to 1 at.% RE, then decreases monotonically with increasing RE content up to 5 at%. The composition dependences of –∆SMpk value with Gd and Dy substitutions display a similar tendency attributed to the change of Fe-Fe magnetic coupling; (3) the RCAREA values of the alloys substituted with 1 at% Gd and Dy are comparable to those of recently reported Fe-based metallic glasses with enhanced RC values compared to those of Gd5Ge1.9Si2Fe0.1 alloy. Enhanced –∆SM and RC values combined to negligible coercive force and hysteresis enable the Fe78−xRExSi4Nb5B12Cu1 amorphous alloys to be lowcost candidates for high-temperature magnetic refrigeration.

References: [1] Warburg E, Magnetische untersuchungen, Ann. Phys., 1881, 13, 141. [2] Franco V, Blázquez JS, Ipus JJ, Law JY, Moreno-Ramírez LM, Conde A, Magnetocaloric effect: From materials research to refrigeration devices, Prog. Mater. Sci., 2018, 93, 112. [3] Huo JJ, Du YS, Cheng G, Wu XF, Ma L, Wang J, et al. Magnetic properties and large magnetocaloric effects of GdPd intermetallic compound. J. Rare Earths, 2018, 36(10), 1044.

[4] Gutfleisch O, Willard MA, Brück E, Chen CH, Sankar SG, Liu JP, Magnetic materials and devices for the 21st century: stronger, lighter, and more energy efficient, Adv. Mater., 2011, 23, 821. [5] Gschneidner KA, Pecharsky Jr VK, Tsokol AO, Recent developments in magnetocaloric materials, Rep. Prog. Phys., 2005, 68, 1479. [6] Zhukov A, Novel Functional Magnetic Materials: Fundamentals and Applications. Berlin, Springer International Publishing, 2016. [7] BASF, Premiere of cutting-edge cooling appliance at CES (2015). Available at https://www.basf.com/cn/en/company/news-andmedia/news-releases/2015/01/p-15100.html. [8] Franco V, Blázquez JS, Conde A, The influence of Co addition on the magnetocaloric effect of Nanoperm-type amorphous alloys, J. Appl. Phys., 2006, 100, 064307. [9] Franco V, Blázquez JS, Millán M, Borrego JM, Conde CF, The magnetocaloric effect in soft magnetic amorphous alloys, J. Appl. Phys., 2007, 101, 09C503. [10] Caballero-Flores R, Franco V, Conde A and Kiss LF, Influence of Mn on the magnetocaloric effect of nanoperm-type alloys, J. Appl. Phys., 2010, 108, 073921. [11] Law JY, Franco V, Ramanujan RV, Influence of La and Ce additions on the magnetocaloric effect of Fe–B–Cr-based amorphous alloys, Appl. Phys. Lett., 2011, 98, 192503. [12] J.Y. Law, R.V. Ramanujan, V. Franco, Tunable Curie temperatures in Gd alloyed Fe-B-Cr magnetocaloric materials, J. Alloys Compd., 2010, 508, 14. [13] Provenzano V, Shapiro AJ, Shull RD, Reduction of hysteresis losses in the magnetic refrigerant Gd5Ge2Si2 by the addition of iron, Nature, 2004, 429, 853. [14] Yano K, Akiyama Y, Tokumitsu K, Kita E, Ino H, Magnetic moment and Curie temperature for amorphous Fe100−xGdx alloys (18≤x≤ 60), J. Magn. Magn. Mater. 2000, 214, 217. [15] Li JW, Huo JT, Law JY, Chang CT, Du J, Man QK, et al. Magnetocaloric effect in heavy rare-earth elements doped Fe-based bulk metallic glasses with tunable Curie temperature, J. Appl. Phys., 2014 116, 063902. [16] Greneche JM, Varret F, On the texture problem in Mossbauer spectroscopy, J. Phys. C, 1982, 15, 5333. [17] J.M. Greneche, F. Varret, A new method of general use to obtain random powder spectra in 57Fe Mössbauer spectroscopy: the rotating-sample recording, J. Phys. Let., 1982, 43, L233.

[18] Chien CL, Unruh KM, Magnetic properties and hyperfine interactions in amorphous FeZr alloys, Phys. Rev. B, 198, 225, 563. [19] Zhao LZ, Li CL, Hao ZP, Liu XL, Liao XF, Zhang JS, et al. Influences of element segregation on the magnetic properties in nanocrystalline Nd-Ce-Fe-B alloys, Mater. Charact., 2019, 148, 208-213. [20] Shen BG, Sun JR, Hu FX, Zhang HW, Cheng ZH. Recent progress in exploring magnetocaloric materials, Adv. Mater., 2009, 21, 4545. [21] Hassini A, Lassri H, Bouhdada A, Ayadi, M, Krishnan R, Mansouri I, et al. Magnetic coupling in amorphous Fe80−xGdxB20 alloys, Phys. B, 2000, 275, 295. [22] Annouar F, Lassri H, Ayadi M, Omri M, Lassri M, Krishnan R, Magnetic exchange coupling in amorphous Fe80−xDyxB20 alloys, J. Alloys Compd., 2005, 397, 42. [23] Wang YY, Bi XF. The role of Zr and B in room temperature magnetic entropy change of FeZrB amorphous alloys, Appl. Phys. Lett., 2009, 95, 262501. [24] Franco V, Conde CF, Blázquez JS, Conde A, Švec P. A constant magnetocaloric response in amorphous alloys with different ratios, J. Appl. Phys., 2007, 101, 093903. [25] Yano K, Kita E, Tokumitsu K, Ino H, Tasaki A. Ferrimagnetic ordering in melt-spun Fe100−xGdx (18≤x≤70) alloys, J. Magn. Magn. Mater., 1992, 104-107, 131. [26] Wood ME, Potter WH. General analysis of magnetic refrigeration and its optimization using a new concept: maximization of refrigerant capacity, Cryogenics, 1985, 25, 667.

Graphical Abstract

The Curie temperature, hyperfine field and magnetic entropy change initially increase with the heavy rare earth (HRE) content up to 1% and then decrease monotonously for increasing HRE content up to 10%.

Table Captions: Table 1 Mean refined values of hyperfine parameters of the Fe78–xDyxSi4Nb5B12Cu1 amorphous alloys

Temperature

IS (mm/s)

2ε (mm/s)

Bhf (T)

$ (°)

(± 0.02)

(± 0.02)

(±0.5)

(±3)

Dy0

0.04

-0.01

20.0

89

Dy1

0.02

–0.01

22.5

46

Dy3

0

0.03

20.2

52

Dy5

0.01

0.00

20.2

47

Dy10

–0.04

0.00

17.4

48

Sample

300 K

Table 2 Values of TC, Tpk, –∆SM pk , and RCAREA of Fe78–xRExSi4Nb5B12Cu1 (RE=Gd, Dy) amorphous alloys under an applied field change of 1.5 T. TC

Tpk

–∆SM pk

RCAREA

(K)

(K)

(J/kg‧K)

(J/kg)

Fe78Si4Nb5B12Cu1

465

475

1.38

89

this work

Fe77Gd1Si4Nb5B12Cu1

548

548

1.66

90

this work

Fe75Gd3Si4Nb5B12Cu1

505

492

1.45

77

this work

Fe73Gd5Si4Nb5B12Cu1

462

467

1.11

69

this work

Fe68Gd10Si4Nb5B12Cu1

502

501

0.97

39

this work

Fe77Dy1Si4Nb5B12Cu1

512

517

1.74

93

this work

Fe75Dy3Si4Nb5B12Cu1

501

501

1.51

78

this work

Fe73Dy5Si4Nb5B12Cu1

499

500

1.56

83

this work

Fe68Dy10Si4Nb5B12Cu1

434

436

1.00

46

this work

Fe77Ce1Si4Nb5B12Cu1

348

348

1.03

78

Ref. 16

Fe75Ce3Si4Nb5B12Cu1

329

329

1.08

79

Ref. 16

Material

Ref.

Fe73Ce5Si4Nb5B12Cu1

305

301

0.93

80

Ref. 16

Fe68Ce10Si4Nb5B12Cu1

281

277

1.00

72

Ref. 16

Figure Captions:

Fig.1. XRD patterns of as-spun Fe78−xRExSi4Nb5B12Cu1 (RE=Gd, Dy) alloys

Fig.2. The RE content dependence of Mössbauer spectra for Fe78-xDyxSi4Nb5B12Cu1 (x=1, 3, 5, and 10) amorphous alloys

Fig. 3. The distribution of the hyperfine field for Fe78-xDyxSi4Nb5B12Cu1 (x=1, 3, 5, and 10) amorphous alloys

Fig.4. Temperature dependences of magnetization and magnetic susceptibility (χ) for Fe77Gd1Si4Nb5B12Cu1 amorphous alloy, measured in an applied field of 0.05T.

Fig.5. (–∆SM)–T curves for Fe78−xRExSi4Nb5B12Cu1 (RE=Gd, Dy) amorphous alloys in an applied field change of 1.5 T

Fig.6. RE content dependences of TC, µeff and –∆SMpk for Fe78−xRExSi4Nb5B12Cu1 (RE=Gd, Dy and Ce) amorphous alloys.