Magnetic and thermal properties of TbMn 2 and Tb(Mn 1 − xA1 x) 2 compounds

Abstract

The effects of A1 substitution for Mn on the magnetic and thermal properties of TbMn 2 have been studied by measuring the temperature dependence of the magnetization, the thermal expansion and the specific heat of Tb(Mn 1 − x A1 x ) 2 compounds. It has been revealed that the substitution of A1 remarkably suppresses the magnetization, resulting in the disappearance of the sharp peak in the thermomagnetic curve characteristic of the helimagnetic transition of TbMn 2. The magnetic specific heat and the magnetic entropy of TbMn 2 and Tb(Mn 0.9A1 0.1) 2 were estimated. A1 substitution wipes out the λ-type peak of the specific heat for TbMn 2. The nature of the magnetic state and the magnetic phase transition in the A1-substituted system is discussed.