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Iron titanate nanopowders with a particle size range of 48-70 nm could be obtained after calcinations of the dried gel at 900 C for 2 h. Fe 2 TiO 5 indicates a ferrimagnetic-paramagnetic behaviour, as evidenced by using vibrating sample magnetometer at room temperature. In the temperature range of 25-300 C the empirical equation of the heat capacity C p (J/mol K) ¼ À692.328 þ 1.39 T þ 3.757 Â 10 7 /T 2 for Fe 2 TiO 5 was determined from differential scanning calorimetry. Direct optical band gap of Fe 2 TiO 5 was calculated using the Tauc model by UV-Vis diffuse reflectance spectroscopy. Band gap energy of Fe 2 TiO 5 was determined as 1.95 eV.

Pure manganese titanate (MnTiO 3 ) nanopowders have been synthesised by stearic acid gel method. Structural investigations by X-ray diffraction and scanning electron microscopy confirm that the synthesised material is MnTiO 3 with rhombohedral crystal structure. Transmission electron microscopy showed that the particle sizes are in the range of 22-30 nm. The formation of MnTiO 3 is further supported by the FT-IR and energy dispersive X-ray spectra. An optical band gap of 3.18 eV is determined for MnTiO 3 nanopowders from the UV-vis absorption spectrum. A broad emission band with maximum intensity at around 487 nm is observed in the photoluminescence spectra of MnTiO 3 nanopowders at room temperature depicting the blue emission, which can be attributed to the