Tuning of the Structure and Magnetocaloric Effect of Mn1−xZrxCoGe Alloys (Where x = 0.03, 0.05, 0.07, and 0.1)

Materials

Karolina Kutynia¹  Piotr Gębara¹ 

[1] Department of Physics, Częstochowa University of Technology, Armii Krajowej 19, 42-200 Częstochowa, Poland;

关键词: magnetocaloric effect;    Heusler alloys;    X-ray diffraction;   

DOI  :  10.3390/ma14113129

来源: DOAJ

【 摘 要 】

The aim of the present work is to study the influence of a partial substitution of Mn by Zr in MnCoGe alloys. The X-ray diffraction (XRD) studies revealed a coexistence of the orthorhombic TiNiSi-type and hexagonal Ni₂In- type phases. The Rietveld analysis showed that the changes in lattice constants and content of recognized phases depended on the Zr addition. The occurrence of structural transformation was detected. This transformation was confirmed by analysis of the temperature dependence of exponent n given in the relation ΔS_M = C·(B_MAX)ⁿ. A decrease of the Curie temperature with an increase of the Zr content in the alloy composition was detected. The magnetic entropy changes were 6.93, 13.42, 3.96, and 2.94 J/(kg K) for Mn_0.97Zr_0.03CoGe, Mn_0.95Zr_0.05CoGe, Mn_0.93Zr_0.07CoGe, and Mn_0.9Zr_0.1CoGe, respectively. A significant rise in the magnetic entropy change for samples doped by Zr (x = 0.05) was caused by structural transformation.

【 授权许可】

Unknown