XANES/EXAFS study of the Lu and Y incorporation in the single crystal Tb3Sc2Al3O12 Faraday rotator

Tb 3Sc 2Al 3O 12 (TSAG) is a paramagnetic insulator which, in spite of its congruent nature and excellent magneto-optical properties as Faraday rotators for optical isolators (OIs), cannot be industrially produced. The reason is that its lattice structure is so stressed that single crystals easily crack upon cooling after growth or during the cutting process. By the incorporation of a small amount of Lu, it has been demonstrated that the stress in the structure can be effectively released, and, therefore, the crystal cracking can be avoided. This has enabled the substitution of standard Tb 3Ga 5O 12 (TGG), achieving better high-power performance and compacter OIs. In this study, the charge state and the lattice site location of Lu as well as Y dopants in TSAG are investigated by X-ray Absorption Near Edge Structure and Extended X-ray Absorption Fine Structure Analysis. Measurements on single crystal and powdered samples indicate that both dopants are incorporated in the 3+ charge state and substitute predominantly in the dodecahedral Tb-site ( >87.5%), while a minor fraction is found in the octahedral Sc-site.Tb 3Sc 2Al 3O 12 (TSAG) is a paramagnetic insulator which, in spite of its congruent nature and excellent magneto-optical properties as Faraday rotators for optical isolators (OIs), cannot be industrially produced. The reason is that its lattice structure is so stressed that single crystals easily crack upon cooling after growth or during the cutting process. By the incorporation of a small amount of Lu, it has been demonstrated that the stress in the structure can be effectively released, and, therefore, the crystal cracking can be avoided. This has enabled the substitution of standard Tb 3Ga 5O 12 (TGG), achieving better high-power performance and compacter OIs. In this study, the charge state and the lattice site location of Lu as well as Y dopants in TSAG are investigated by X-ray Absorption Near Edge Structure and Extended X-ray Absorption Fine Structure Analysis. Measurements on single crystal and powdered samples indicate that both dopants are incorporated in the 3+ charge stat...