EPR of transition metals in fluoroaluminate glasses

摘要: Abstract The results of EPR study fluoroaluminate glasses (FAG) in the AlF3-YF3-RF2 system (where R = Mg, Ca, Sr, Ba) doped with small amounts transition metals (Ti, V, Mn, Fe, Co, Cu) are presented. spectrum Ti3+ ions FAG is similar to that reported for many and can be described by g1 1.96 g2 1.91 at 77 K. vanadium-containing exhibit only when V introduced as vanadium oxides; this belongs VO2+ an axial spin-Hamiltonian parameters (determined fitting experimental simulated spectra): g∥ 1.949; g⊥ 1.980; A∥ 163 × 10−4 cm−1; A⊥ 63 cm−1. An X-band Mn2+ consists a well-resolved sextet near g 2.0 weak background ≅ 4.3 resonances. hyperfine splitting resonance measured Q-band A 98.5±0.5 Oe. Concentration dependence permits one assume more uniform distribution than HMFG where these believed clustered. Iron present predominately Fe2+ ions. portion Fe3+ gives which oxide but very different from observed HMFG. By contrast fluoroberyllate signals Co2+ have been K broad single line centered ∼ 4.2 spectra containing copper superpositions isolated Cu2+ almost isotropic belonging presumably crystalline occlusions undergo cooperative Jahn-Teller effect. dissolved exhibits superhyperfine structure about 50 Oe interaction unpaired electrons 19F nuclei.