Optical and e.s.r. absorption and electrical conductivity in KCl:Pd crystals

Abstract
Three opticals absorption bands peaking at 360, 272 and at about 200 nm are obtained in KCl crystals doped with palladium. The band peaking at 272nm is the most intense. The 272nm band is attributed to the intra-ionic absorption in the Pd2+ ions in the crystal, the 360nm band to the charge transfer spectra and the band at about 200nm to the excitation of host anions perturbed by the impurity ions. F centres cannot be formed in Pd-doped crystals by additive or electrolytic coloration. Instead an absorption band peaking at 218nm is observed and the bands observed prior to coloration disappear. The band at 218nm is attributed to the colloidal particles of palladium. Esr spectra show six hyperfine lines superimposed over a broad line. The Pd-doped crystals show enhanced electrical conductivity.