Specific features of magnetic properties of rare-earth ferroborates Sm1 − x La x Fe3(BO3)4

Single crystals of rare-earth ferroborates Sm1 − x La x Fe3(BO3)4 (x = 0, 0.5, 0.75) have been grown by the flux method. Their magnetic properties have been investigated in the temperature range from 2 to 300 K in magnetic fields up to 9 T. It has been found that the substitution of nonmagnetic ions La3+ for magnetic ions Sm3+ in Sm1 − x La x Fe3(BO3)4 ferroborates leads to an increase in the magnetic susceptibility of the compound. The behavior of the magnetic properties of the grown single crystals has been explained qualitatively in the framework of the phenomenological model. The parameters of d-d and d-f exchange interactions have been estimated.