EPR-SPECTRA OF NANOCRYSTALLINE COMPOSITE OXIDES LA1-XSRXFEO3 WITH A PEROVSKITE STRUCTURE

Nanocrystals La1-xSrxFeO3 (x = 0.0, 0.1, 0.2, 0.4 and 0.6), containing crystal grains of mean diameter 12.4 nm (x = 0.0) and 4-7 nm (x = 0.1-0.6), were compacted into nanocrystalline solid materials under static pressures of 0.5, 1.0 and 1.5 GPa in the axial direction at ambient temperature. The results showed that the peak intensities of the electron paramagnetic resonance (EPR) spectra for the nanocrystalline solid materials were about 10(3)-10(4) times stronger than those of conventional crystals. The EPR spectra changed with grain size and compacting pressure. The characteristics of the EPR spectra of these nanocrystalline solid materials are discussed.