Accession Number : AD0617993

Title :   DIELECTRIC DISPERSION OF SOME PEROVSKITE ZIRCONATES,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE SPECTROSCOPY LAB

Personal Author(s) : Perry,C. H. ; McCarthy,D. J. ; Rupprecht,G.

Report Date : 06 JAN 1965

Pagination or Media Count : 2

Abstract : The dielectric properties of perovskites have been the subject of many investigations, but a direct correlation between the dielectric constant and a normal optically active lattice mode has been convincingly established only in the case of the paraelectric strontium titanate. The identification of this so-called 'soft' mode is still debated. Such an assignment of the normal-mode spectrum in perovskites is now achieved by a comparison of the normal modes of titanates and zirconates. In addition, evidence is presented that also in the case of an antiferroelectric material, lead zirconate, the low-frequency dielectric constant is the result of a low-frequency optically active mode, at K = O, whose contribution tothe dielectric constant accounts for about 90% of its value at room temperature. (Author)

Descriptors :   (*ZIRCONATES, DIELECTRIC PROPERTIES), (*DIELECTRIC PROPERTIES, ZIRCONATES), CALCIUM COMPOUNDS, STRONTIUM COMPOUNDS, BARIUM COMPOUNDS, LEAD COMPOUNDS, TITANATES, REFLECTION, SPECTROSCOPY, CRYSTAL LATTICES, ANTIFERROELECTRICITY

Distribution Statement : APPROVED FOR PUBLIC RELEASE