Glass-to-Vitroceramic Transition in the Yttrium Aluminoborate System: Structural Studies by Solid-State NMR

Autor(es)

Deters, Heinz ^{[1, 2]} ; de Camargo, Andrea S. S. ^{[3, 1]} ; Santos, Cristiane N. ^[3] ; Eckert, Hellmut ^[1]

Afiliação do(s) autor(es)

^[1] WWU Munster, Inst Phys Chem, D-48149 Munster - Germany

^[2] WWU Munster, Grad Sch Chem, D-48149 Munster - Germany

^[3] Univ Sao Paulo, Inst Fis Sao Carlos, Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Physical Chemistry C; v. 114, n. 34, p. 14618-14626, SEP 2 2010.
• Citações Web of Science: 11

Resumo

The crystallization of laser glasses in the system (B(2)O(3))(0.6)[(Al(2)O(3))(0.4-y)(Y(2)O(3))(y)] (0.1 <= y <= 0.25) doped with different levels of ytterbium oxide has been investigated by X-ray powder diffraction, differential thermal analysis, and various solid-state NMR techniques. The homogeneous glasses undergo major phase segregation processes resulting in crystalline YBO(3), crystalline YAI(3)(BO(3))(4), and residual glassy B(2)O(3) as the major products. This process can be analyzed in a quantitative fashion by solid-state (11)B, (27)Al, and (89)Y NMR spectroscopies as well as (11)B[(27)Al] rotational echo double resonance (REDOR) experiments. The Yb dopants end up in both of the crystalline components, producing increased line widths of the corresponding (11)B, (27)Al, and (89)Y NMR resonances that depend linearly on the Yb/Y substitution ratio. A preliminary analysis of the composition dependence suggests that the Yb(3+) dopant is not perfectly equipartitioned between both crystalline phases, suggesting a moderate preference of Yb to substitute in the crystalline YBO(3) component. (AU)

• Processo FAPESP: 04/00093-0 - Síntese e caracterização de componentes micro-ópticos bifuncionais e filmes amorfos dos sistemas RE: Y2O3 - Al2O3 - B2O3 e RE: Y2O3 - CaO - B2O3 (RE = Nd, Er, Sm) para aplicação em micro-óptica e luminescência
• Beneficiário: Cristiane Nascimento Santos
• Modalidade de apoio: Bolsas no Brasil - Doutorado