Phase analysis and magnetocaloric properties of Zr substituted Gd-Si-Ge alloys

作者：Prabahar K; Kumar D M Raj; Raja M Manivel^*; Chandrasekaran V

来源：Journal of Magnetism and Magnetic Materials, 2011, 323(13): 1755-1759.

DOI：10.1016/j.jmmm.2011.01.029

• Gd-Si-Ge alloy
• Magnetocaloric effect
• Microstructure
• Magneto-structural transition

The structure, microstructure, magneto-structural transition and magnetocaloric effect have been investigated in series of (Gd(5-x)Zr(x))Si(2)Ge(2) alloys with 0 <= x >= 0.20. X-ray powder diffraction analysis revealed the presence of orthorhombic structure for Zr containing alloys at room temperature in contrast to the monoclinic structure observed in the parent Gd(5)Si(2)Ge(2) alloy. The microstructural studies reveal that, low Zr addition (x <= 0.1) resulted in low volume fraction of detrimental Gd(5)Si(3)-type secondary phase compared to that present in the parent alloy. All the Zr containing alloys have shown the presence of only second order magnetic transition unlike the parent alloy showing both first order structural and second order magnetic transition. A moderate (Delta S)(M) value of -5.5 J/kg K was obtained for the x = 0.05 alloy at an enhanced operating temperature of 292 K compared to -7.8 J/kg K at 274 K of the parent alloy for an applied field of 2 T. The interesting feature of Zr (x = 0.05) containing alloy is the wide operating temperature range of similar to 25 K than that of similar to 10-12 K for the parent, which resulted in enhanced net refrigerant capacity of 103 J/kg compared to that of 53 J/kg for the parent alloy.

• 出版日期2011-7