Magnetic properties of the ternary aluminide TbFe2Al10

Abstract

The magnetic properties of the ternary aluminide TbFe2Al10 have been studied with the help of magnetization measurements. From the temperature and field dependence of magnetization, a detailed magnetic phase diagram of TbFe2Al10 has been constructed. While the high- and low-temperature phases (in low fields) of TbFe2Al10 are paramagnetic and antiferromagnetic respectively, the signature of a field-induced ferromagnetic phase is obtained in the magnetization results in the intermediate temperature regime. While it was already known that TbFe2Al10 has a ferrimagnetic phase in between the low-field antiferromagnetic and the high-field ferromagnetic phases, the present results indicate the presence of a second intermediate-field-induced ferrimagnetic phase in the compound, in between the first ferrimagnetic and the high-field ferromagnetic phases. The possible magnetic structure for this second ferrimagnetic phase is proposed on the basis of existing neutron diffraction results. The successive field-induced or metamagnetic transitions in TbFe2Al10 are found to be induced by temperature as well, when the applied magnetic field is appropriate. The present magnetization results also indicate the presence of short-range magnetic correlations in TbFe2Al10 well inside the paramagnetic regime. Owing to the presence of successive temperature and field-induced magnetic phase transitions, TbFe2Al10 is found to exhibit a moderate magneto-caloric effect with a maximum of 7.86 J kg−1K−1 at 18.5 K. The magneto-caloric effect is found to persist well inside the paramagnetic regime because of the presence of short-range magnetic correlations at these temperatures. This leads to a substantial refrigerant capacity in the material, which could be useful information for future technology.