Manifestation of magnetoelastic interactions in Raman spectra of Ho x Nd 1 - X Fe3(BO3)4 crystals

Abstract

Raman spectra of Ho1-xNdxFe(BO3)4 (x=1, 0.75, 0.5, 0.25) have been studied in temperature range 10-400K. Two compositions (x=1, x=0.75) demonstrate structural phase transition with soft mode restoration. The addition of Nd atoms increases interatomic spacing and decreases the temperature of structural phase transition. The solid solutions (x=0.75, 0.5, 0.25) demonstrate the emergence of the peaks corresponding to magnetoelastic interaction below Néel temperature. The order parameter of the magnetic phase transition has been determined. The equal concentrations of holmium and neodymium atoms prevent magnon soft modes condensation caused by exchange interactions in Fe-O-Fe chains are observed. Calculations confirm the data obtained in the experiment.