材料期刊网

The effects of substitution of Al for Co on magnetic and magnetocaloric properties of MnCo_1-xAl_xGe (x=0.00, 0.03, 0.05, 0.08, 0.10, 0.13, 0.15, and 0.20) compounds have been investigated by X-ray diffraction (XRD) and magnetization measurements. XRD exhibits that MnCo_1-xAlxGe compounds crystallize in the orthorhombic TiNiSi-type structure for x≤0.03 and in the hexagonal Ni₂In-type crystal structure for x>0.03. Magnetic measurements show that the Curie temperature can be tuned between 286 and 347 K by changing the Co/Al ratio. The maximum magnetic entropy change determined from the isothermal magnetization measurement by Maxwell relation reaches 1.52 J/(kgK) for x=0.08 in a field change from 0 to 1.5 T around 310 K.