Paramagnetic Resonance Investigation of Irradiated KCl Crystals Containing<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>U</mml:mi></mml:math>-Centers

Abstract

The effects of ultraviolet irradiation of KCl---KH and KCl---KD single crystals at 80\ifmmode^\circ\else\textdegree\fi{}K and 300\ifmmode^\circ\else\textdegree\fi{}K have been investigated using paramagnetic resonance and optical absorption techniques. KCl---KH crystals irradiated at 80\ifmmode^\circ\else\textdegree\fi{}K have been found to exhibit, along with the usual $F$-center spin resonance, a resonance doublet with a splitting of 500\ifmmode\pm\else\textpm\fi{}10 gauss and a line width of 68\ifmmode\pm\else\textpm\fi{}5 gauss; the doublet is presumed to be due to hydrogen atoms in the crystal. This conclusion is substantiated by the fact that KCl---KD crystals, after a similar irradiation, exhibit a resonance triplet with a separation of outer components of 156\ifmmode\pm\else\textpm\fi{}10 gauss. Further results lead to the following conclusions: (1) that the hydrogen atoms produced by irradiation are located in interstitial positions in the lattice, (2) that these interstitial hydrogen atoms give rise to an optical absorption band (${U}_{2}$-band) located at 236 m\ensuremath{\mu}, (3) that a broad optical absorption band (${U}_{1}$-band) extending to the long wavelength side of the $U$-band is due to interstitial hydride ions.