Spectroscopic study of stoichiometry deviation in crystals with garnet structure

Abstract

Stoichiometry deviations in aluminium and gallium garnet crystals are investigated by measuring the spectra of rare-earth impurities ions as indicator. All garnet crystals prepared from the melt are found to have a nonstoichometric composition due to incorporation of some part of the rare-earth ions into Al3± or Ga3± octahedral sites. The stoichiometry deviations in the homologous series of aluminium and gallium garnet crystals are estimated quantitatively. The spectra of Er3± ions occupying a-sites with octahedral oxygen environment in garnet lattice are registered and studied. An effect is found of difference in the sizes of the rare-earth ions on their co-occupation of octahedral sites in the gallium garnet lattice.