Rotating magnetocaloric effect over a wide room temperature range in oriented polycrystalline Nd1 − xTbxCo5

Abstract

Oriented polycrystalline Nd1 − xTbxCo5 alloys are fabricated successfully by the magnetic field bonding technique, and magnetocrystalline anisotropy (MCA) and rotating magnetocaloric effect (RMCE) have been studied systematically. Two successive spin-reorientation transitions (SRTs), “easy-plane” to “easy-cone” transition at TSR1 followed by “easy-cone” to “easy-axis” transition at TSR2, are observed. The SRT temperatures shift toward room temperature due to the enhancement of MCA by substituting Nd with Tb of a higher MCA constant. In addition, two competing mechanisms on MCA might be induced by substituting Nd with Tb, which leads to the nonlinear variation of RMCE. The RMCE and the working temperature range increase largely by substituting Nd with a small amount of Tb, e.g., the maximum rotating adiabatic temperature change ΔTrot increases by ∼60% from x = 0 to 0.1. The relatively large RMCE over a wide working temperature range (from 240 K to 310 K) makes x = 0.1 compound attractive candidate for rotating magnetic refrigeration around room temperature.