Crystal Field for Yb3+ in Garnets

摘要: Nine parameters Anm〈rn〉 are necessary to define the crystal field acting on rare‐earth ions in garnets, and a priori none of these may be considered negligible. As there general insufficient data determine from experiment alone, we have attempted reduce number unknowns by estimating ratio terms same degree an accurate point charge calculation, leaving only effective values 〈r2〉, 〈r4〉, 〈r6〉 determined observed electron spin resonance optical data. Calculations for garnet lattices show that all nine quite important. There significant contributions more distant than eight nearest oxygen neighbors usually considered, frequently used approximation near cubic symmetry is poor. large uncertainty two second it therefore treat both A20〈r2〉 A22〈r2〉 as unknowns.Ytterbium simplest rare earths consider th...