Estle, Thomas L.2016-04-222016-04-221970Shen, Lewis Nai-Sing. "Paramagnetic resonance of transition group ions in crystals with the fluorite structure." (1970) Master’s Thesis, Rice University. <a href="https://hdl.handle.net/1911/90066">https://hdl.handle.net/1911/90066</a>.https://hdl.handle.net/1911/90066The electronic paramagnetic resonance of Co2+ in cubic sites of CaF2 and in trigonal sites of CdF2 have been observed at a frequency of 9 GHz and at liquid helium temperature. The trigonal spectra have an axial symmetry about a (lll) direction with g11 = 2.25 +/- 0.05 and g1 = 4.45 +/- 0.10. The origin of this trigonal center is unknown. The isotropic spectra can be described by a spin Hamiltonian with g = 2.32 +/- 0.01, u=-0.Oil +/- 0.004, A = 27.5 +/- 1.2 x lO-4 cm-1 and U = 3.5 +/- 3.5 x 10-4cm-1. The superhyperfine splitting parameters are estimated to be Af = 2.85 x 10-4cm-1 and Bf = 5.97 x lO-4cm-1. Heat treatment of the doped Ca?2 sample makes the cubic spectra diminish. This phenomenon is explained by a change in the valence' state of the paramagnetic ion. X-ray irradiation of the CaF2 sample doped with Co by diffusion changes the sample to red, but no Co^ + ions are observed. Attempts to convert the cubic spectra to trigonal ones by oxidation and hydrolysis do not yield any result.80 ppengCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.ThesisRICE1102reformatted digitalThesis Phys. 1970 Shen