Spectroscopic studies of samarium chromium borate SmCr$_3$(BO$_{3}$)$_4$

The optical spectra, thermal and magnetic properties of the compound SmCr$_3$(BO$_3$)$_4$ were investigated in a wide temperature range. A series of phase transitions at temperatures of T$_1$ =8,0 ± 0,5К, T$_2$=6,7 ±0,5К and T$_3$=4,3 ± 0,2К. were found. First two transitions at the temperatures T1 and T2 are second order phase transitions and, most likely, correspond to antiferromagnetic ordering of subsystem Cr$^{3+}$ and, then, crystal transition to the ferroelectric state. First-order phase transition at a temperature of 4,2 ± 0,2K most likely corresponds to the spin-reorientation of the chromium magnetic moments.