I. Omkaram

Structural and Magnetic Properties of Cr Doped SnO2 Nanopowders Prepared by Solid State Reaction

Chromium-doped tin oxide nano powders (Sn1-xCrxO2, x = 0.00, 0.03, 0.05 and 0.07) were prepared using simple low cost solid state reaction and followed by vacuum annealing at 900 o C and studied the effects of Cr dopant concentration on structural and magnetic properties. The X-ray diffraction (XRD) studies confirmed that all the diffracted peaks were polycrystalline rutile structure of SnO2 phase. FT-IR analysis gave additional supports of formation of O-Sn-O and Cr-Sn-O the system. Magnetic studies revealed that all the powder samples were ferromagnetic at room temperature. Further the saturation magnetization increased with increase of doping concentration.

Raman and FT-IR studies of (In0.90Sn0.05Fe0.05)2O3 nanoparticles

ITO (In0.95Sn0.05)2O3 and Fe doped ITO (In0.90Sn0.05Fe0.05)2O3 nanoparticles were synthesized using standard solid state reaction and characterized by XRD, Raman and FT-IR studies, UV-Vis-NIR spectrophotometer and vibrating sample magnetometer for structural, optical and magnetic properties.The XRD patterns revealed the formation of nanocrystalline particles with cubic bixbyte crystal structure. The Raman spectra show that the nanoparticles are free of secondary crystalline phase.From FT-IR studies it was found that the bonds observed were due to In2O3 and no new peaks were found in FT-IR spectra. This clearly indicatesthat Fe ions are incorporate into the host In2O3 structure and does not alter the crystal structure of In2O3 host material. The undoped ITO nanoparticles exhibited room temperature ferromagnetism with clear hysteresis curve having coercive field of 683 G whereas the same ITO nanoparticles exhibited coercive field of 150 G at 100 K.