ESR- und optische Untersuchungen am Triplett-Zustand von NaNO2-Kristallen / ESR and Optical Investigations on the Triplet State of NaNO2 Crystals

Abstract

The metastable triplet state Ti of N02 in NaNO2 single crystals was investigated at temperatures between 1,4 and 4,2°K by ESR-, by phosphorescence- and by level crossing-experiments From these measurements we find the zerofield splitting parameters:D/hc = (0,444 ± 0,005) cm-1,E/hc = -(0,045 ± 0,005) cm-1,g = 2,002 ± 0,003,where the z-axis is taken parallel to the line connecting the two O-atoms. The optically detected magnetic resonance (ODMR) and the phophorescence spectra in magnetic fields up to 50 kOe give evidence for optical spin polarisation. The kinetic constants for the population, the radiative decay and the total decay of each zerofield component of T1 could be estimated as follows: the zerofield level tx is preferentially populated; the decay is radiative for ty and nonradiative for tx and tz.