PAC Characterization of Nontransformable Tetragonalt′ Phase in Arc-Melted Zirconia-2.8 mol% Yttria Ceramics

Autor: Patricia C. Rivas, Agustín M. Rodríguez, Sergio R. Mintzer, María C. Caracoche, Alberto F. Pasquevich
Rok vydání: 2001
Předmět:
Zdroj: Journal of the American Ceramic Society. 84:188-192
ISSN: 1551-2916
0002-7820
DOI: 10.1111/j.1151-2916.2001.tb00629.x
Popis: Tetragonal compact bodies obtained by quenching from the melt a ZrO 2 -2.8 mol% Y 2 O 3 commercial powder have been investigated between room temperature and 1150°C, using mainly perturbed angular correlations spectroscopy. The resulting nontransformable t' phase observed by optical micrography is characterized at nanoscopic level by a hyperfine interaction describing defective and disordered Zr 4+ neighborhoods very different from those of the regular tetragonal phase. A small amount of remaining Zr 4+ sites corresponds to a scarcely distorted tetragonal structure. As the compacts are heated, two processes activate: the movement of vacancies and the gradual and irreversible conversion of t' defective sites into less defective ones, probably resulting from oxygen absorption.
Databáze: OpenAIRE
Nepřihlášeným uživatelům se plný text nezobrazuje
načítá se...