Structural phase transition in TbFe2.5Ga0.5(BO3)(4)single crystal

The Raman spectra of the TbFe2.5Ga0.5(BO3)(4)single crystal in the temperature range from 8 to 400 K have been observed. The condensation and restoration of the soft modes have been found. The soft modes are associated with the structural phase transition from theR32 phase to theP3(1)21 phase. The behavior of the hard modes confirms the structural phase transition close to the tricritical point. The temperature of the structural phase transitionT(1)= 33 K is established.