I.V.V. Dipoles in LiF:Ti

Abstract

ITC technique is exploited to search dipolar defects, induced in LiF by Ti, whose valence state is not well known. ITC spectra (78–350 K) exhibit at least one peak at 235 K: 1) its amplitude increases with nominal Ti-concentration and annealing temperature; 2) its shape does not depend on thermal treatment nor on Ti-concentration nor on the dopant type (TİO2 or Li2TiF6);3) it is not a single peak; 4) it is very weak in air grown crystals. Critical analysis of ITC data compared with optical and EPR spectra suggest that Ti3+ compensated by two cation vacancies is responsible for 235 K peak.