Mössbauer Effect for Fe 57 in Ferroelectric BaTi O 3 . II…
1966; American Institute of Physics; Volume: 149; Issue: 1 Linguagem: Inglês
10.1103/physrev.149.289
ISSN1536-6065
Autores Tópico(s)Ferroelectric and Piezoelectric Materials
ResumoIn the study of ferroelectric BaTi${\mathrm{O}}_{3}$ using the ${\mathrm{Fe}}^{57}$ M\"ossbauer probe, a variety of environments are encountered by the impurity probes. Velocity spectra have been analyzed to show that the ${\mathrm{Ti}}^{4+}$ substitution by the probe ${({\mathrm{Co}}^{57})}^{2+}\ensuremath{\rightarrow}{({\mathrm{Fe}}^{57m})}^{3+}$ or stable ${({\mathrm{Fe}}^{57})}^{3+}$ results generally in localized charge-compensating oxygen vacancies. Polarization experiments show that the impurity-vacancy complexes are rotatable. The oxygen vacancies are believed to be of the axial type (OI oxygens) in tetragonal BaTi${\mathrm{O}}_{3}$. Large nonstoichiometry in reduced samples has been shown to induce an ${\mathrm{Fe}}^{2+}$ state.
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