Electron Paramagnetic Resonance in SrTiO3

The intensities of paramagnetic resonance lines in SrTi${\mathrm{O}}_3$ have been correlated to the iron concentrations. Evidence for attributing the origin of the resonance in titanates to iron impurities ${(\mathrm{F}\mathrm{e}}^{3+}$) rather than to the domain structure was obtained. In SrTi${\mathrm{O}}_3$, resonance experiments over the temperature range 300°K to 1.9°K show a slow continuous increase of the tetragonal component of the crystalline field down to the ferroelectric region. From intensity considerations the absolute signs of the crystalline splitting parameters have been determined.