CHARGE CONVERSION OF IRRADIATED RARE-EARTH IONS IN CaF$sub 2$. II. THERMOLUMINESCENT SPECTRA.

摘要: High-resolution emission spectra are observed for individual glow peaks from all the lanthanide ions in Ca${\mathrm{F}}_{2}$. The crystals irradiated with x rays (or $\ensuremath{\gamma}$ rays) at 77\ifmmode^\circ\else\textdegree\fi{} and subsequently heated. For a given ion, identical below 300\ifmmode^\circ\else\textdegree\fi{}K. In cases where can be interpreted, responsible these sites of cubic symmetry. some this is first time that has been seen without complication accompanying lower above room temperature always axial symmetry, which ${\mathrm{Gd}}^{3+}$ identified as tetragonal. Comparison also made between Ca${\mathrm{F}}_{2}$, Sr${\mathrm{F}}_{2}$, Ba${\mathrm{F}}_{2}$. last two both trigonal symmetry temperature.