Magnetic susceptibility and heat capacity of Ho0.5Nd0.5Fe3(BO3)4

The magnetic properties of trigonal Ho0.5Nd0.5Fe3(BO3)4 substituted compound with the competitive Ho–Fe and Nd–Fe exchange interactions have been investigated theoretically. The spontaneous spin-reorientation transition near 9 K has been described. The increase in temperature of the spin-reorientation transition in Ho0.5Nd0.5Fe3(BO3)4 to 9 K in comparison with 5 K in HoFe3(BO3)4 was explained. The calculations were performed using a molecular-field approximation and a crystal-field model for the rare-earth subsystem. A good agreement between the experimental and calculated temperature dependences of magnetic susceptibility and heat capacity has been achieved.