SiO2/SnO2 and Sn/Sb-oxide/SiO2 gel-derived composites. Part 2: Thermal evolution and phase analysis |
| |
Authors: | G Carturan R Ceccato R Campostrini V M Sglavo |
| |
Institution: | (1) Dipartimento di Ingegneria dei Materiali, Università di Trento, Via Mesiano 77, 38050 Trento, Italy |
| |
Abstract: | The thermal behaviour of samples with nominal composition 80/20=SiO2/SnO2, class B, 76.8/19.2/4.0=SiO2/SnO2/Sb2O5, class C1, and 76.8/19.2/2.0/2.0=SiO2/SnO2/Sb2O5/Sb2O3, class C2, is studied in the interval 25–1050°C by various instrumental methods. Results on these classes of samples, obtained from
alkoxide precursors, are compared themselves and with samples of class A obtained from Si(OEt)4 and SnCl4. The segregation and crystallization of SnO2 occurs at 400°C in the presence of microdomains of SnO2·nH2O in the SiO2 gel matrix (class A), whereas it is observed at 700°C for samples B and C composed of Sn and Sb cations homogeneously dispersed
in SiO2. This fact implies different mechanisms of SnO2 nucleation and growth. The crystallization of SiO2 is observed at 1200°C for samples A, at 1050°C for B and at 800°C for C. For this latter, the presence of Sb-oxide/ SiO2 reactive glass is invoked to the low-temperature crystallization of SiO2.
G. Carturan, R. Ceccato, R. Campostrini, G. Principi, and U. Russo, submitted to J. Sol-Gel Sci. Tech. |
| |
Keywords: | thermal behavior crystalline phases energy content densities infrared spectra |
本文献已被 SpringerLink 等数据库收录! |
|