ESR Study of Mo³⁺ Containing Mixed Yttrium–Scandium–Aluminium Garnet Single Crystals

Abstract

ESR ofMo3+ ions in mixed single crystals of yttrium-scandium-aluminium garnets Y3A12-zSc, a -A130,,, where 0 5 x 5 2 is investigated. Several new centers of Mo3f differing from those for Y&OIZ single crystals are observed due to changes of symmetry and crystal field parameters associated with isomorphous substitution of octahedrally coordinated AP+ (a) by those of Sc3+ in the third coordination sphere. Symmetry, nearest coordination, and spin-Hamiltonian parameters are estimated concerning with all Mo3+ centers in Y,Al~-,Sc,Al,O,, crystals for x < 0.15. It is found that in Y,Sc,AI,O,, (x = 2) the Scs+ ions substitute also YS+ a t dodecahedra1 sites. klCCJIea;OBaH 3nP EIOHOB M03+ B MOHOKpYICTaJIJIaX CMeIIIaHHbIX EITTpHn-CKaHflEIfi-aJIH)MHtMeBbIX QaHaTOB YsAla-&&130,,, ra;e 0 5 x 5 2. O 6~a p y r n e~ pfIA HOBbIX, IIO CpaBHeHMH) C Y,AI,O,, , IIapaMWHElTHbIX UeHTpOB MOS' 06ycno~ne~~b1x EI3MeHeHYI-OHTa3RPH4eCKH KOOP~HHEpOBaHHbIX EIOHOB Ala+ (a) Ha SC3+ B TpeTbeP KOOpflEIHaUEIOHHO& CnHH raMHJIbTOHElaHOB BCeX UeHTpOB MOS+ B KpHCTaJIJI2lX Y & -z S C ,~~O ,~ IIpH IIMH cmmeTpm EI napaMeTpoB KpucTannHsecHoro n o m n p~ EIBOMOP$IHOM ~M~I U~H H E I caepe. YcraHosneHhi CHMMIT~NH, 6nm~afimee oxpymeme II onpea;eneHM naparae.rpar z < 0,15. no~asaH0, ¶TO B cnysae Y3Sc,Al,0,, HOHH ScS+ 3a~eLJmI0T TaKme EIOHbX Ys+ B a ; o a ; e~a 3~~s e c m x nonornemmx.

YAG:Ce Nanophosphors Synthesized by the Polymer–Salt Method for White LEDs with Isomorphic Substitution of Yttrium by Gadolinium

“…For example, the isomorphic substitution of yttrium or aluminum by other ions modifies significantly the properties of materials doped with activator ions [15,21,22]. The partial substitution of aluminum (ionic radius 0.53 Å) by scandium (0.75 Å) in order to form paramagnetic centers in Mo 3+ -doped YAG was described in [21].…”