Critical behaviour of the RCo3B2 (RÂ =Â Gd, Tb and Dy) compounds

The critical properties of RCo3B2 (R = Gd, Tb, and Dy) compounds around the rare earth sublattice magnetic phase transition have been investigated by using the field dependence of magnetic entropy change method. The obtained values of critical exponents for all the compounds satisfied with the scaling theory. The critical behaviour of RCo3B2 compounds lies between mean-field model and 3D Heisenberg model, close to Tricritical mean-field model, and close to 3D Ising model for R = Gd, Tb, and Dy, respectively. The present results have confirmed that the field dependence of magnetic entropy change method can be applied to study the critical behaviour of magnetic materials.