Magnetic transitions and thermomagnetic properties of GdCu6

Abstract We report results of dc magnetization and specific heat studies focusing on the paramagnetic to antiferromagnetic transition in GdCu6. These results clearly reveal the evidences of multiple magnetic transitions in GdCu6. In addition, a marked thermomagnetic irreversibility is observed in the temperature dependence of magnetization in low ( 10 kOe ) applied magnetic fields. Nature of the magnetic response changes with the increase in applied magnetic field in the temperature regime around the paramagnetic–antiferromagnetic transition temperature and also well inside the antiferromagnetic state. Experimentally measured specific heat in GdCu6 is quite large in the temperature regime below 20 K, which indicates to the potential of GdCu6 as a magnetic regenerator material for cryocooler related applications. Isothermal magnetic entropy change estimated from the results of magnetization and specific heat measurements shows a change in sign at the antiferromagnetic ordering temperature.