Hyperfine interaction of impurity hydrogen atoms in alkaline-earth fluorides

Abstract

The hydrogen atom, being the simplest of all atoms, has received much attention not only as an isolated entity but also as an impurity in a host crystal. The relative shift of its Isotropic hyperfine (hf) interaction, Δ a/ a o = ( a — a 0)/ a o, serves as a direct indicator for electron density accumulation or depletion at the hydrogen impurity compared to a free hydrogen atom. Two empirical scaling relations have recently been found for hf shifts of interstitial hydrogen atoms H o i in alkali halide (AX) crystals [Bucher M., Phys. Rev. B44, 5309 (1991)]. The scaling relations give insights into binding of the host-impurity complex and also predict hf interactions of H o i atoms in AX hosts that have not been measured yet. In this note I report similar scaling relations of hf shifts of impurity hydrogen atoms in alkaline-earth fluorides.