Facet-Related Site Selectivity for Rare-Earth Ions in Yttrium Aluminum Garnet

Abstract

We have measured the spin-resonance spectra of crystals cut from beneath {110} and {112} facets of flux-grown yttrium aluminum garnet doped with ${\mathrm{Nd}}^{3+}$ and ${\mathrm{Yb}}^{3+}$. Sites which are crystallographically equivalent, but differ in their orientation relative to the facet normal, are found to be unequally populated. Such site preference can account in principle for the recently reported noncubic magnetocrystalline anisotropy of mixed rare-earth iron garnets.