Effect of microstructure and texture on the magnetic and magnetocaloric properties of the melt-spun rare earth intermetallic compound DyNi

摘要

Magnetization measurements have been carried out on the melt-spun ribbon sample of the rare earth intermetallic compound DyNi (Orthorhombic, FeB-type, Space group Pnma) and its magnetic and magnetocaloric properties are compared with those of the arc-melted analog. The arc-melted DyNi orders ferromagnetically at around 61 K (T_C) whereas the melt-spun DyNi orders ferromagnetically at about 47 K. The maximum isothermal magnetic entropy change, ΔS_m~(max), near T_C of the arc-melted and the melt-spun DyNi is found to be -32.7 J/kg K and -22.4 J/kg K, respectively, for a field change of 140 kOe. For low magnetic field changes of_20 kOe, the relative cooling power (RCP) is ～660 J/kg for the arc melted DyNi and ～460 J/kg for the melt-spun ribbon. The reduction in T_C and magnetocaloric effect may be attributed to the microstructure-induced anisotropy developed during the melt-spinning process.