ESR Study of Mo 3+ Containing Mixed Yttrium–Scandium–Aluminium Garnet Single Crystals

ESR of Mo 3+ ions in mixed single crystals of yttrium–scandium–aluminium garnets Y 3 Al 2− x Sc x . Al 3 O 12 , where 0 ≦ x ≦ 2 is investigated. Several new centers of Mo 3+ differing from those for Y 3 Al 5 O 12 single crystals are observed due to changes of symmetry and crystal field parameters associated with isomorphous substitution of octahedrally coordinated Al 3+ (a) by those of Sc 3+ in the third coordination sphere. Symmetry, nearest coordination, and spin–Hamiltonian parameters are estimated concerning with all Mo 3+ centers in Y 3 Al 2− x Sc x Al 3 O 12 crystals for x < 0.15. It is found that in Y 3 Sc 2 Al 3 O 12 ( x = 2) the Sc 3+ ions substitute also Y 3+ at dodecahedral sites.