Laser-induced time-resolved luminescence of Cr³⁺ in kyanite

M. Gaft, L. Nagli

 Laser Distance Spectrometry (LDS), Petach Tikva, Israel

G. Panczer

Physical Chemistry of Luminescence Materials Laboratory, Lyon 1 University, UMR 5620 CNRS, Villeurbanne, France

GR. Rossman

 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, USA 91125-2500

Abstract

Laser-induced time resolved luminescence spectroscopy was applied for kyanite luminescence study to clarify the origin of well known narrow emission lines with long decay times. Based on kinetic and polarized luminescence experiments, it is proposed that they are connected to transitions from ²E_g and ²T₁ levels of Cr³⁺ luminescence center in a site of intermediate crystal within the kyanite structure. It contradicts the generally accepted interpretation that they are transitions from a split ²E_g level of a Cr³⁺ luminescence center in a strong crystal field position. Some ideas are presented on the origin of narrow lines with short decay times and broad luminescence bands.