Vibrational normal modes of SiO2. III. agr;hyphen;Berlinite (AlPO4) and its relations to Ggr;ndash;Aphonon dispersion curves in agr;hyphen;quartz

摘要

The valence force field, previously obtained to describe the vibrational normal modes of quartz, cristobalite, and tridymite forms of SiO2(parts I and II), has been used to calculate the phonon dispersion curves and elastic constants of agr;hyphen;quartz. The reasonably good fit to the experimental data suggested that the same valence force field may be valid in agr;hyphen;berlinite, an isomorph of agr;hyphen;quartz. The following results confirm the analogy between SiO2and AlPO4.