Metal-nonmetal transition of lanthanum hydrides, analyzed by 139La hyperfine interaction

Lanthanum hydrides $\mathrm{La}{\mathrm{H}}_{x},\phantom{\rule{0.3em}{0ex}}2.0\ensuremath{\leqslant}x\ensuremath{\leqslant}3.0$, are characterized by static magnetic susceptibility analysis and $^{139}\mathrm{La}$ nuclear magnetic resonance investigations (line splittings, linewidth, line shift, and spin lattice relaxation). Temperature and composition dependence of all quantities is determined. Chemical shift is larger than the Knight shift for $^{139}\mathrm{La}$ in the $\mathrm{La}{\mathrm{H}}_{x}$ compounds. The $x$ dependence of the density of states $D({E}_{F})$ is derived site selectively and separated into $s$- and $d$-like contributions.