Temperature effects of optical phonon for ZrH1.7 and PdH0.7

The optical phonon spectra for ZrH1.7 (containing 0.2% C) and PdH0.7 are measured at room temperature and low temperature (97 K) with beryllium filter detector spectrometer adjacent to the heavy water pile in the Instisute of Atomic Eenrgy. The results show that: (1) Optical phonon energy level for ZrH1.7 is equal essentially spacing, the width of energy level essentially does not change with T, i.e. the anharmonicity of optical phonon is weak and it obeys Einstein harmonic model; (2) The second optical phonon energy level spacing for PdH0.7 is about 8 MeV large than that of the first level spacing, and the width of its optical phonon energy level changes from 38 MeV at room temperature to 20 MeV at 97 K. This means that the optical phonons which play an important role in super conductivity of PdHx exhibit significant anharmonicity