Piyush Kumar Patel

Reduced dielectric loss in Ba0.95Sr0.05(Fe0.5Nb0.5)O3 thin film grown by pulsed laser deposition

Thin films of Ba0.95Sr0.05(Fe0.5Nb0.5)O3 ceramic on ITO-coated glass substrate were prepared by pulsed laser deposition technique. Deposited films were annealed at 500 °C for 1 h in vacuum. Structural, dielectric and optical properties were studied at different substrate temperature. Thin films were analyzed using low angle X-ray diffraction. All thin films have a single-phase perovskite structure. AFM analysis showed the uniform and nanosize grains in all samples. At room temperature, high dielectric constant (∼4037) with low dielectric loss (0.04) was obtained at 1 kHz frequency. The optical band gap was found to be 2.60 eV for 550 °C deposited film.

Crystal structure analysis of lead free Ba{sub 1-x}La{sub x}[Ti{sub 0.5}(Fe{sub 0.5}Nb{sub 0.5}){sub 0.5}]{sub 1-x/4}O{sub 3} Ceramics

Single phase Ba1-xLax[Ti0.5(Fe0.5Nb0.5)0.5]1-x/4O3 [referred as BT-LFN]; x=0, 0.02, 0.04 and 0.06 ceramics have been synthesized by solid – state reaction process and were characterized by X-ray diffraction technique. The microstructure of the ceramics was examined by field emission-scanning electron microscopy (FE-SEM).

Magnetocapacitance and Magnetic Properties of Cr³+ Ions Doped Hematite Prepared by Sol-Gel Method at Room Temperature

Hematite (α-Fe2O3) and 5 mol.% Cr3+ ions doped hematite were synthesized by sol gel method. X-ray diffraction (XRD) patterns of powder calcined at 500 0C show the formation of single-phase rhombohedral structure. Thermogravimetric (TG) analysis of as prepared powder indicates the formation of sample around 400 0C. FESEM analysis shows grain size of sintered pellets ~ 100 nm. Magnetization of hematite powders was found to be higher compared with Cr3+ ions doped hematite at the same magnetic field (10 kOe). We observed magnetocapacitance in both the systems at room temperature. As neither hematite nor Cr3+ ions doped hematite is multiferroic material, the observed magnetodielectric property is believed to arise from extrinsic effect such as magnetoresistance. Keywords—Sol-gel; Magnetic materials; Hematite; X-ray diffraction.