Lattice dynamics study and specific heat ofCsH2PO4andCsD2PO4

Ya. Shchur
2006 Physical Review B  
This paper reports the results of lattice dynamics simulation of CsH 2 PO 4 and CsD 2 PO 4 crystals in paraelectric and ferroelectric phase using a semiempirical atomistic model based on the Coulomb, short range, covalent, and van der Waals interactions. The peculiarity of the two types of hydrogen bonds is taken into consideration too. The tunneling of protons ͑deuterons͒ on the one type of hydrogen bonds above the phase transition point was simplified through keeping the H͑D͒ atom position at
more » ... D͒ atom position at the middle in hydrogen bonds. Phonon density of states, partial density of states, isotropic temperature factors, and specific heat were calculated. The computed phonon frequencies are particularly useful in interpreting the complicated Raman and IR spectra of these hydrogen-bonded crystals. The specific heat experimental data, reported by two groups of authors, contradict each other. The results of the given simulation may be helpful in establishing the real temperature behavior of specific heat.
doi:10.1103/physrevb.74.054301 fatcat:hu7pl4g7trb47btcyssdm454r4