Temperature dependence of anomalous and ordinary Raman scattering in β-AgI

We report careful measurements of the temperature dependence of Raman scattering in β-AgI, with particular emphasis on the region 12°K to 150°K. Our main result is that the anomalous features in the Raman spectra of β-AgI are definitely first order. Furthermore from the temperature dependence of the anomalous scattering intensity we infer the possibility of a first partial disordering in the Ag⁺ sublattice at about 50°K.