Magnetism, heat capacity, magnetocaloric effect and magneto-transport in R₂Al (R = Nd, Gd, Tb) compounds

Magnetic, magneto-thermal and magneto-transport properties investigated in R₂Al compounds reveal interesting aspects regarding the magnetic state of these compounds. The coexistence of ferro and antiferro magnetic order is seen to determine the magnetic and other related properties. The crystal field effect is found to be significant in Nd and Tb compounds, as revealed by the magnetization and heat capacity data. The sign of the isothermal magnetic entropy change reflects the nature of magnetic transitions. The magnetic entropy change is found to be significant in all the three compounds, with Tb ₂Al showing the maximum value of 12 J kg^-1 K^-1. Like the entropy change, the magnetoresistance (MR) also shows different signs, reflecting the magnetic state. At low temperatures, all the compounds show very large MR.