Paramagnetic Resonance ofS-State Ions in Strontium Chloride

Abstract

Paramagnetic resonance spectra have been observed of ${\mathrm{Mn}}^{2+}$, ${\mathrm{Gd}}^{3+}$, and ${\mathrm{Eu}}^{2+}$ in single crystals of strontium chloride grown from the melt. The ${\mathrm{Mn}}^{2+}$ shows a very small cubic-field splitting $a<\mathrm{}1\mathrm{}\times {10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$ and a hyperfine structure constant of $A=81.2\mathrm{}\times {10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$, indicating some covalent bonding. The ${\mathrm{Gd}}^{3+}$ and ${\mathrm{Eu}}^{2+}$ have cubic symmetry with splitting parameters, for ${\mathrm{Gd}}^{3+}$: $c=\pm (39.6\mathrm{}\pm 0.1)\times {10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$, $d=\mp (0.2\mathrm{}\pm 0.1)\times {10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$, $g=1.9906\mathrm{}\pm 0.001$; for ${\mathrm{Eu}}^{2+}$: $c=(52\mathrm{}\pm 5)\times {10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$, ${\mathrm{A}}^{151}$=(34.5±0.3)×${10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$, ${\mathrm{A}}^{153}$=(15.5±0.3)×${10}^{-4\mathrm{}}$ ${\mathrm{cm}}^{-1\mathrm{}}$, $g=1.995\mathrm{}\pm 0.001$.