sábado, 13 de marzo de 2010

FW: Lattice dynamics study and specific heat of CsH2PO4 and CsD2PO4


From: loquitalinda_16@hotmail.com
To: jamalaguera.56448227@blogger.com
Subject: Lattice dynamics study and specific heat of CsH2PO4 and CsD2PO4
Date: Sat, 13 Mar 2010 17:08:19 +0000


Ya. Shchur
Institute for Condensed Matter Physics, vul. Svientsits'kogo 1, 79011 L'viv, Ukraine
Received 11 January 2006; revised 7 April 2006; published 1 August 2006
This paper reports the results of lattice dynamics simulation of CsH2PO4and CsD2PO4 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 (deuterons) on the one type of hydrogen bonds above the phase transition point was simplified through keeping the H(D) 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.
ROSSANA HERNANDEZ
CI 19234948
ESTADO SOLIDO




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