Influence of manganese substitution into the A-site of perovskite type Ca1−xMnxTiO3 ceramic

Ca1−xMnxTiO3 (x = 0–1.0) perovskite ceramics were prepared by conventional solid state reaction. XRD was used to confirm the microcrystalline nature of the Ca1−xMnxTiO3 crystals. For the x = 0 composition, the XRD patterns were those of a single orthorhombic perovskite while for x = 0.2–0.8, the XRD spectra were those of two orthorhombic perovskite phases: CaTiO3 and MnTiO3. For x = 1, XRD pattern was that of the MnTiO3 phase only. The morphology and particle size of the grains of the different composition were observed using SEM. The size of the particles increased from 0.2 μm to 2–3 μm as x increased from 0 to 0.6. The room temperature dielectric constant at the frequency of 110 kHz for the x = 0.2 and x = 1.0 ceramics were ∼3.41 × 104 and ∼4.99 × 103, respectively. The ESR linewidth of samples increased with increasing manganese content due to the formation of magnetic cluster. Our ESR studies indicate that the manganese ions are in the Mn4+ state.