Thermal behavior of the amorphous precursors of the ZrO{sub 2}-SnO{sub 2} system

Journal Article · Mon Nov 03 00:00:00 EST 2008 · Materials Research Bulletin

DOI:https://doi.org/10.1016/j.materresbull.2007.12.016· OSTI ID:21143956

Stefanic, Goran ^[1]; Music, Svetozar; Ivanda, Mile ^[1]

---

1. Division of Materials Chemistry, Rugjer Boskovic Institute, P.O. Box 180, HR-10002 Zagreb (Croatia)

Thermal behavior of the amorphous precursors of the ZrO{sub 2}-SnO{sub 2} system on the ZrO{sub 2}-rich side of the concentration range, prepared by co-precipitation from aqueous solutions of the corresponding salts, was monitored using differential thermal analysis, X-ray powder diffraction, Raman spectroscopy, field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectrometry (EDS). The crystallization temperature of the amorphous precursors increased with an increase in the SnO{sub 2} content, from 405 deg. C (0 mol% SnO{sub 2}) to 500 deg. C (40 mol% SnO{sub 2}). Maximum solubility of Sn{sup 4+} ions in the ZrO{sub 2} lattice ({approx}25 mol%) occurred in the metastable products obtained upon crystallization of the amorphous precursors. A precise determination of unit-cell parameters, using both Rietveld and Le Bail refinements of the powder diffraction patterns, shows that the incorporation of Sn{sup 4+} ions causes an asymmetric distortion of the monoclinic ZrO{sub 2} lattice. The results of phase analysis indicate that the incorporation of Sn{sup 4+} ions has no influence on the stabilization of cubic ZrO{sub 2} and negligible influence on the stabilization of tetragonal ZrO{sub 2}. Partial stabilization of tetragonal ZrO{sub 2} in products having a tin content above its solid-solubility limit was attributed to the influence of ZrO{sub 2}-SnO{sub 2} surface interactions. In addition to phases closely structurally related to cassiterite, monoclinic ZrO{sub 2} and tetragonal ZrO{sub 2}, a small amount of metastable ZrSnO{sub 4} phase appeared in the crystallization products of samples with 40 and 50 mol% of SnO{sub 2} calcined at 1000 deg. C. Further temperature treatments caused a decrease in and disappearance of metastable phases. The results of the micro-structural analysis show that the sinterability of the crystallization products significantly decreases with an increase in the SnO{sub 2} content.

• OSTI ID: 21143956
• Journal Information: Materials Research Bulletin, Vol. 43, Issue 11; Other Information: DOI: 10.1016/j.materresbull.2007.12.016; PII: S0025-5408(08)00002-0; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AQUEOUS SOLUTIONS
COPRECIPITATION
CRYSTALLIZATION
DIFFERENTIAL THERMAL ANALYSIS
MICROSTRUCTURE
MONOCLINIC LATTICES
RAMAN SPECTROSCOPY
SCANNING ELECTRON MICROSCOPY
SOLUBILITY
STABILIZATION
TEMPERATURE RANGE 0400-1000 K
TIN IONS
TIN OXIDES
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY
ZIRCONIUM OXIDES