Resumo

MEJIA-URIARTE, E.V. et al. Determination of Phase Transition by Principal Component Analysis Applied to Raman Spectra of Polycristalline BATIO₃ at Low and High Temperature. J. appl. res. technol [online]. 2012, vol.10, n.1, pp.57-62. ISSN 2448-6736.

This work describes the principal component analysis (PCA) applied to Raman spectra of polycrystalline BaTiO₃ as a function of temperature. During each experiment the samples was continuously heated and the Raman spectrum was registered every 0.5 °C at a rate of 0.1 °C min-1. This procedure is applied on samples BaTiO₃ compact powder to obtain their thermal behavior from -190 °C to 230 °C. The PCA method was able to distinguish spectral features to determine the phase transition temperature and the whole thermal history including the structural phase transition from rhombohedra to orthorhombic at -100 °C, orthorhombic to tetragonal at -5 °C and tetragonal to cubic at 121 °C.

Palavras-chave : Phase transitions; BaTiO3; principal component analysis.

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