Comparative study of the magnetoelectric effect in HoAl$_{3}$(BO$_{3}$)$_{4}$ and HoGa$_{3}$(BO$_{3}$)$_{4}$ single crystals

The comparative study of the magnetoelectric properties and magnetostriction of HoGa$_{3}$(BO$_{3}$)$_{4}$ and HoAl$_{3}$(BO$_{3}$)$_{4}$ single crystals has been carried out. The investigated compounds exhibit qualitatively similar magnetodielectric and inverse magnetoelectric $ME_E$ effects with the close absolute values, which is indicative of the weak effect of a nonmagnetic metal ion. On the contrary, the magnetostriction of the galloborate has been found to be threefold higher than that of the alumoborate. In addition, the difference between the qualitative behaviors of magnetostriction has been established: the magnetic-field dependence of magnetostriction for the alumoborate has the maximum near 70 kOe at $T$ = 4.2 K, while the galloborate magnetostriction has no maximum and does not saturate in a field of 140 kOe.