ESR investigation of ferroelectric films

The investigation of SrTiO3: Ca, Cr, PbZr0.58Ti0.42O3 and PbTiO3 ferroelect ric films on the substrate of Al2O3 and MgO single crystals respectively wa s performed by ESR method. Study of the SrTiO3 films with the thickness h = 17000 Angstrom and 3500 Angstrom doped by 0.1% Cr and 0.2% Ca was carried out at T = 18 K with and without illumination of ultraviolet light (lambda = 365 nm). Analysis of the observed spectra had shown that there were two C r3+ ESR lines with g-factors 1.977 and 1.974 in the thick film whereas in t hin film there was line with g = 1.974 with higher intensity than that in t hick Film. Calculations lead to the conclusion that the line with smaller g -factor belongs to Cr3+ centers nearby films surface. Small intensity line with g = 2.002 revealed in the films most probably belongs to O- center. It s intensity increases after illumination, but it conserves even without ill umination contrary to the bulk samples. ESR spectra of PZT and PT films wer e recorded at T = 77 K and 300 K for different orientations of magnetic fie ld. Analysis have shown that the spectra origin is Cr, Mn, V and Fe impurit y ions. The influence of the revealed defects and impurities on the propert ies of the films is discussed.