Effect of α-Fe impurities on the field dependence of magnetocaloric response in LaFe11.5Si1.5

JOURNAL OF ALLOYS AND COMPOUNDS

卷:646

Article

Blazquez, J. S.¹  Moreno-Ramirez, L. M.¹  Ipus, J. J.¹  Kiss, L. F.²  Kaptas, D.²  Kemeny, T.²  Franco, V.¹  Conde, A.¹ 

[1] Univ Seville, Dept Fis Mat Condensada, ICMSE CSIC, E-41080 Seville, Spain

[2] Hungarian Acad Sci, Wigner Res Ctr Phys, H-1525 Budapest, Hungary

关键词: Magnetocaloric effect;    Field dependence;    Multiphase systems;   

DOI  :  10.1016/j.jallcom.2015.06.085

来源: Elsevier

【 摘 要 】

In this work, the theoretical field dependence of the magnetic entropy change far away from the transition is used to analyze the field dependence of composite materials formed by fcc La(Fe,Si)(13) and bcc alpha-Fe(Si) phases. A non-interacting phases approximation is followed in the analysis and results are in good agreement with microstructural data obtained from X-ray diffraction and Mossbauer spectroscopy. The range of validity of the approximation is estimated. It is concluded that the quadratic field dependence of magnetic entropy change is reached a few tens of kelvin above the transition temperature at 1.5 T. However, the linear dependence (characteristic of ferromagnets well below its Curie temperature) is only reached a few hundred kelvin below the transition. The results presented here can be used in the deconvolution of the contribution of impurities to the MCE signal in composites. (C) 2015 Elsevier B.V. All rights reserved.

【 授权许可】

Free