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

Abstract

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 61K (TC) whereas the melt-spun DyNi orders ferromagnetically at about 47K. The maximum isothermal magnetic entropy change, ∆Smmax, near TC of the arc-melted and the melt-spun DyNi is found to be −32.7J/kgK and −22.4J/kgK, respectively, for a field change of 140kOe. For low magnetic field changes of ~20kOe, the relative cooling power (RCP) is ~660J/kg for the arc melted DyNi and ~460J/kg for the melt-spun ribbon. The reduction in TC and magnetocaloric effect may be attributed to the microstructure-induced anisotropy developed during the melt-spinning process.