Magnetocaloric effect studies on MnSbR<inf>0.05</inf> (R: Gd, Tb, Dy and Ho) intermetallics

Abstract

Magnetocaloric effect studies (MCE) at high temperatures are attractive from the point of view of large change in magnetic entropy (ΔS M ) in magnetic refrigeration. While materials which exhibit first order magnetic transition (FOMT) are prominent materials to exhibit large ΔS M , they also exhibit thermal hysteresis [1]. Therefore, focus on materials exhibiting second order magnetic transition (SOMT) with large ΔS M at low applied magnetic fields is important for magnetic refrigeration. Thus, large magnetic moments and sharp magnetic transition at Curie temperature are prerequisites for a material to be considered for magnetic refrigeration applications. In general, heavy rare-earth elements and their compounds are considered as good MCE materials due to their large magnetic moments [2]. However, low Curie temperatures and large anisotropy have forced the rare earth elements to be combined with other compounds, for applications. MnSb is a SOMT with the magnetic transition temperature (T C ) well above room temperature [3]. Therefore, an attempt was made to study the MCE at high temperatures in MnSb with 5 % excess of heavy rare-earths (R: Gd, Tb, Dy and Ho).