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Electron spin resonance investigation of Mn^{2+} ions and their dynamics in manganese doped SrTiO_3

V. V. Laguta·I. V. Kondakova·I. P. Bykov·M. D. Glinchuk·P. M. Vilarinho·A. Tkach·L. Jastrabik
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Abstract

Using electron spin resonance, lattice position and dynamic properties of Mn2+ ions were studied in 0.5 and 2 % manganese doped SrTiO3 ceramics prepared by conventional mixed oxide method. The measurements showed that Mn2+ ions substitute preferably up to 97 % for Sr if the ceramics is prepared with a deficit of Sr ions. Motional narrowing of the Mn2+ ESR spectrum was observed when temperature increases from 120 K to 240-250 K that was explained as a manifestation of off-center position of this ion at the Sr site. From the analysis of the ESR spectra the activation energy Ea = 86 mV and frequency factor 1/?0 ? (2-10)x10^(-14) 1/s for jumping of the impurity between symmetrical off-center positions were determined. Both values are in agreement with those derived previously from dielectric relaxation. This proves the origin of dielectric anomalies in SrTiO3:Mn as those produced by the reorientation dynamics of Mn2+ dipoles.

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V. V. Laguta, I. V. Kondakova, I. P. Bykov, M. D. Glinchuk, P. M. Vilarinho, A. Tkach, L. Jastrabik. 2007-02-28. Electron spin resonance investigation of Mn^{2+} ions and their dynamics in manganese doped SrTiO_3. https://doi.org/10.1103/physrevb.76.054104

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