Electron paramagnetic resonance study of the BaCrO4 polycrystalline γ-irradiated

An EPR study of the paramagnetic centres formed by γ-irradiation of polycrystalline BaCrO4 was made. In the EPR spectra of the γ-irradiated powder samples, at room temperature, the presence of three types of paramagnetic centres was observed. According to their EPR parameters and thermal behaviour, these centres were attributed to the CrO4-, CrO3- and CrO2- radicals, respectively. The intensity of the signal attributed to the CrO4- radical strongly depends on the conditions of sample preparation. A mechanism of paramagnetic centres formation in γ-irradiated BaCrO4 was proposed, taking into account the contribution of the impurities. (author)