ESR Studies of Radiation-Damage Centers in Barium Sulfide

Single crystals of BaS have been grown and irradiated with neutrons, producing an intense $F$-center spectrum with a spectroscopic splitting factor, $g=1.9637\mathrm{}\pm 0.0005$. The isotropic part of the hyperfine interaction $A$ is 41.0±0.2 and 36.4±0.2 G for the nearest-neighbor ${}_{}{}^{137}{}_{}{}^{}\mathrm{Ba}$ and ${}_{}{}^{135}{}_{}{}^{}\mathrm{Ba}$ nuclei, respectively. The dipolar hyperfine interaction constants $B$ are found to be 4.0±0.1 and 3.8±0.1 G, respectively, for the same nuclei. $F$ centers were also observed in samples which had been crushed or $\gamma$-irradiated following deformation. Other damage centers were observed with less intensity than the $F$ center and are briefly discussed.