Raman scattering in the two-dimensional antiferromagnet MnPSe3

Raman spectra of the two-dimensional antiferromagnet MnPSe 3 are measured in the temperature region between 18 and 297 K. Below T N =74+or-2 K an anomalous enhancement of some Raman-active phonon peaks is observed. A new phonon peak appears below T N at 86 cm -1 . The relation between its behaviour and the magnetic ordering as explained in terms of the spin-dependent phonon Raman process. A peak at 133 cm -1 (T=18 K) shifts to low frequency with increasing temperature and disappears above T N . It is assigned to a one-magnon Raman peak.