Microstructure development and Raman responses of mechanically activated Fe/BaTiO3

Abstract

The structure and lattice dynamics of mechanically activated nanocrystalline Fe/BaTiO3 is investigated in this work. The powder mixture of 60% Fe and 40% BaTiO3 was mechanically activated up to 240 min in 500 cm3 zirconium oxide beakers together with balls of 10 mm in diameter (the ratio of powder and balls was 1:20). The microstructure development has been studied by scanning electron microscope equipped with energy dispersive X-ray analysis spectrometer. Room temperature Raman spectra of the samples were obtained in the spectral range from 100 to 1650 cm-1, in the backscattering geometry, using 633 nm line of a He-Ne laser. Raman spectroscopy was employed to investigate the laser power dependence of the spectra of the activated samples as well. Microstructural investigations showed that mechanical activation has led to the creation of new surfaces and the comminution of the initial powder particles. Raman spectroscopy analysis pointed out that activation had a pronounced influence on Fe/BaTiO3 lattice spectra, thus affecting both the stability of the crystal structure and the phase transition phenomena.