Accession Number : AD0669350

Title :   INVESTIGATION ON COLOR CENTERS AND LUMINESCENCE IN INSULATING CRYSTALS.

Descriptive Note : Final scientific rept. 1 Nov 66-31 Dec 67,

Corporate Author : HEBREW UNIV JERUSALEM (ISRAEL) DEPT OF PHYSICS

Personal Author(s) : Halperin,Abraham ; Braner,Abraham A. ; Cohen,Z. ; Shapira,J. ; Zacks,E.

Report Date : FEB 1968

Pagination or Media Count : 43

Abstract : Thermally stimulated luminescence (TSL) and conductivity (TSC) in KBr, x-excited at LAT were measured simultaneously. Most TSL peaks were correlated to TSC peaks. Re-excitation with F-light resulted in high intensity TSC peaks at 143 and 218K and low TSL at 146 and 223K. V light gave different results. Optical bleaching of the F- or F'-bands increased some and reduced other glow peaks. Hexagonal (6H-alpha SiC) silicon carbide crystals including iron and nitrogen were examined. The absorption showed weak bands at 0.62 and about 0.9 microns. The decay of the blue luminescence nearly fitted a power law with slopes of less than one for decay times up to 2msec. Short wavelength components of the band decayed faster compared with those at longer wavelengths. The TSL showed one glow peak near 115K with an activation energy of 0.12-0.13 ev. The TSL and TSC of a Brazilian natural quartz crystal and a synthetic Ge-doped sample as well as their re-excitation and bleaching effects are also described. (Author)

Descriptors :   (*DIELECTRICS, *LUMINESCENCE), (*COLOR CENTERS, DIELECTRICS), POTASSIUM COMPOUNDS, BROMIDES, THERMOLUMINESCENCE, THERMAL CONDUCTIVITY, EMISSIVITY, SILICON CARBIDES, IMPURITIES, IRON, NITROGEN, ABSORPTION SPECTRA, RELAXATION TIME, QUARTZ, GERMANIUM, ISRAEL

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE