Characterization and dielectric properties of SrTi1-xMnxO3 ceramics

摘要

SrTi1- xMnxO3 (x = 0, 0.05, 0.10, and 0.15) ceramics can be prepared by sintering SrTi1- xMnxO3 nanopowders, synthesized by a hydrothermal method, at 1,200 degrees C in air for 3 h. X-ray diffraction (XRD) results for all nanopowders and unannealed ceramics indicate a cubic-perovskite structure with an impurity phase of SrCO3 in nanopowders of x = 0.10 and 0.15. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images of nanopowders reveal the agglomeration of cubiclike nanoparticles with particle sizes in the range of 86-105 nm. The dielectric constant (epsilon') at room temperature tends to increase upon Mn doping, to the maximum value of 600 at 1 kHz for a ceramic sample of x = 0.05 owing to the homogeneity of grain sizes. Annealing of ceramic samples can also increase the epsilon' values through the creation of oxygen vacancies. (C) 2015 The Japan Society of Applied Physics