Raman spectroscopy study of Zn1-xFexSe under high pressure

Zn1-xFexSe, x = 0, 0.018, 0.035 and 0.16, were studied by Raman scattering spectroscopy up to 35.0 GPa, Lt was found that the semiconductor-metal phas e transition pressures for these samples are 14.4, 12.8, 12.0 and 10.9 Cpa, respectively. Before the semiconductor-metal phase transition, a visible a nomaly of the TO Raman mode splitting was observed at 4.7 and 9.1 GPa for Z nSe, at 3.3 and 5.9 GPa for Zn0.982Fe0.018Se, and at 4.5 and 7.2 Cpa for Zn 0.965Fe0.035Se, respectively, while Zn0.84Fe0.16Se showed mode splitting at 4.7 GPa only. For these samples, one of the TO splitting modes exhibits ph onon softening (red shift), while the other manifests wavenumber increasing (blue shift) with pressure. For x = 0.018, 0.035 and 0.16, a new Raman mod e, which was identified as Fe local mode, was observed between the pure ZnS e LO and TO modes, Fe local mode exhibits blue shift behaviour before metal lization and disappears as the pressure is higher beyond the metallization pressure. PACS numbers: 62.50. + p, 64.60. - i, 78.30.Fs. Copyright (C) 199 9 John Wiley & Sons, Ltd.