A new perovskite-based titano-manganate, (La0.4Ba 0.4Ca0.2)(Mn0.4Ti0.6)O3, has been prepared by the ceramic route at 1100°C. This oxide was found to possess the cubic perovskite structure with 'a'=3.9477(23)Å (space group Pm3̄m). The refined composition as obtained by Rietveld analysis of powder X-ray data was found to be (La0.44Ba0.38Ca 0.18)(Mn0.43Ti0.57)O2.91(3) (R p=0.0704, wRp=0.0828). The composition was also ascertained by Energy dispersive X-ray analysis. Iodometric studies led to a slightly higher oxygen content (compared to Rietveld refinement) corresponding to an average manganese oxidation state of 3.05. The above oxide was found to exhibit high dielectric constant (ε) of 6980 at 1kHz decreasing to 590 at 100kHz. At high temperatures (200°C) it shows an unusually high dielectric constant of 20,000 at 1kHz. In addition to the dielectric properties, detailed magnetic studies show evidence of long-range antiferromagnetic interactions near 5K. The presence of unusually high dielectric constant coupled with the long-range magnetic interactions may open up interesting applications.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Condensed Matter Physics
- Physical and Theoretical Chemistry
- Inorganic Chemistry
- Materials Chemistry