Synthesis dependent characteristics of Sr1−xMnxTiO3 (x=0.03, 0.05, 0.07 and 0.09)

Sr1−xMnxTiO3 (where x=0.03, 0.05, 0.07 and 0.09) was synthesized via different routes that include solid-state, oxalate precipitation and freeze drying. In oxalate precipitation technique, compositions corresponding to 3 and 5 mol% doping of Mn were monophasic whereas the higher compositions revealed the presence of the secondary phases such as MnO, Mn3O4 etc., as confirmed by high resolution X-ray diffraction (XRD) studies. The decomposition behavior of the precursors prepared using oxalate precipitation method corresponding to the above mentioned compositions was studied. Nanopowders of compositions pertaining to 5 to 9 mol% of Mn doping were obtained using freeze–drying technique. The average crystallite size of these nanopowders was found to be in the 35 to 65 nm range. The microstructural studies carried out on the sintered ceramics, fabricated using powders synthesized by different routes established the fine grained nature (<1 μm) of the one obtained by freeze drying method. Raman scattering studies were carried out in order to complement the observations made from XRD regarding the phase purity. The dielectric properties of the ceramics obtained by different synthesis routes were studied in the 80–300 K temperature range at 100 kHz and the effect of grain size has been discussed.

XRD patterns of Sr1−xMnxTiO3 (x=0.03 and 0.05) obtained by oxalate precipitation technique along with that of the nanopowders for x=0.05, 0.07 and 0.09 obtained by freeze drying method, microstructural characterization and synthesis dependent dielectric behavior.Figure optionsDownload as PowerPoint slideHighlights
► Monophasic samples obtained for compositions Sr1−xMnxTiO3 with x=0.03 and 0.05.
► Nanopowders of Sr1−xMnxTiO3 with x=0.05, 0.07 and 0.09 were synthesized by freeze–drying method.
► Phase purity of samples synthesized using freeze drying method were studied at different sintering temperatures.
► Analysis of Raman spectra for samples prepared by both oxalate precipitation and freeze–drying.
► Microstructure dependent dielectric characteristics have been illustrated.