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PAC Characterization of Nontransformable Tetragonal t ′ Phase in Arc‐Melted Zirconia–2.8 mol% Yttria Ceramics
Author(s) -
Rodríguez Agustín M.,
Caracoche María C.,
Rivas Patricia C.,
Pasquevich Alberto F.,
Mintzer Sergio R.
Publication year - 2001
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2001.tb00629.x
Subject(s) - tetragonal crystal system , materials science , yttria stabilized zirconia , phase (matter) , cubic zirconia , quenching (fluorescence) , analytical chemistry (journal) , ceramic , crystallography , metallurgy , chemistry , optics , fluorescence , physics , organic chemistry , chromatography
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.