Accession Number : ADA267074
Title : Nanocomposites for Electronic Applications. Volume 2.
Descriptive Note : Final rept. 1 Jan 90-31 Dec 91,
Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK MATERIALS RESEARCH LAB
Personal Author(s) : Cross, L. E.
Report Date : 14 JUN 1993
Pagination or Media Count : 173
Abstract : Work on this program and associated studies on the ONR program on 'Piezoelectric and Electrostrictive materials for Transducer Applications' has lead to a significantly improved understanding of the fundamental mechanisms in Relaxor Ferroelectrics. For the perovskite Lead Magnesium Niobate which is the prototype for many other relaxor perovskites, the self limiting nonstoichiometric ordering of Mg/Nb ions is shown to be the symmetry breaking key to the onset of micropolar regions at the Burns temperature well above the dielectric maximum. The simple paraelectric behavior at high temperature is shown to be modified by cooperation on cooling, leading to a Vogel:Fulcher type condensation into a glass like state at low temperature
Descriptors : *DIELECTRICS, *FERROELECTRICITY, *RELAXATION, NIOBATES, LEAD COMPOUNDS, MAGNESIUM COMPOUNDS, SPECTROSCOPY.
Subject Categories : Physical Chemistry
Electrical and Electronic Equipment
Distribution Statement : APPROVED FOR PUBLIC RELEASE