Far IR spectra of Ag_2CdI_4at temperature range 10-420 K:complementary experimental and first-principle theoretical study

摘要

The influence of temperature on the far-infrared (FIR) spectrum of polycrystalline Ag_2CdI_4hasbeen investigated by Fourier Transform Infrared (FTIR) spectroscopy measurements. The FIR phononspectrum has also been calculated by means of quantum mechanical density functional theory (DFT). Thecomparison of calculated and measured spectra allows the fast and reliable assignment of the measuredphonon modes, and thus clarifies the mode splitting character obtained at elevated temperatures.