Electron Spin Resonance of theZ1Band in KCl with SrCl2

Abstract

The electron spin resonance (ESR) associated with the $Z_1$ optical absorption in KCl: Sr has been observed in association with the $F$-center ESR. By an extrapolation procedure, it is found that the $Z_1$ ESR is characterized by a $g$ value of 1.9952±0.0005 and a derivative peak-to-peak width of 63±1 Oe. A Gaussian shape for the $Z_1$ ESR is strongly inferred. Preliminary results obtained with $F$ and $Z_2$ centers present indicate that the $Z_2$ ESR has a slightly larger $g$ value and a somewhat greater width than the $Z_1$ ESR. Optical absorption parameters of $h{\nu }_{max}=2.068\mathrm{}\pm 0.005$ eV (599 mμ) and $W=0.290\mathrm{}\pm 0.005$ eV are found for the $Z_1$ band at liquid nitrogen temperature.