Irshad Bhat

Synthesis and characterization of electron doped La0.85Te0.15MnO3 thin film grown on LaAlO3 substrate by pulsed laser deposition technique

We report the structural, morphological and magneto-transport properties of electron doped La0.85Te0.15MnO3 (LTMO) thin film grown on (001) LaAlO3 single crystal substrate by pulsed laser deposition (PLD). X-ray diffraction (XRD) results confirm that the film has good crystalline quality, single phase, and c-axis orientation. The atomic force microscopy (AFM) results have revealed that the film consists of grains with the average size in a range of 20–30 nm and root-mean square (rms) roughness of 0.27nm. The resistivity versus temperature measurement exhibits an insulator to metal transition (MIT). We have noticed a huge value of magnetoresistance (∼93%) close to MIT in presence of 8T field. X-ray photoemission spectroscopy confirms the electron doping and suggests that Te ions could be in the Te4+ state, while the Mn ions stay in the Mn2+ and Mn3+ valence state.

Structural, optical and antimicrobial studies of 3β-acetoxycholest-5-ene, 3β-acetoxy-6-nitrocholest-5-ene and newly synthesized steroidal pyrazolones

Abstract A convenient synthesis of a new series of nano steroidal pyrazolones is reported. They were characterized by X-ray diffraction, scanning electron microscopy, UV–vis light, Fourier transform-infrared spectroscopy, 1H and 13C nuclear magnetic resonance, mass spectroscopy and analytical data. The X-ray diffraction patterns at room temperature showed that two nano steroids, 7 and 8, are formed in single phase with hexagonal crystal symmetry, while nano steroid 9 is formed with orthorhombic crystal symmetry. Compounds 1–3 are formed with hexagonal, monoclinic and tetragonal crystal symmetry, respectively. Scanning electron microscopy showed that the crystals of nano steroids 7–9 are brick-shaped agglomerates with less sharp edges and a rough surface with a few microcrystals, while the homogeneous crystal of nano steroid 3 has an approximate spherical morphology of nano particles conjoined to the chains. UV–vis absorption analysis showed that the band gap energy of nano steroids 7 and 8 was 3.70 eV and 4.61 eV, while that of 2 and 3 was 4.38 eV and 4.27 eV, respectively. Nano steroids 2, 3 and 7–9 were screened for antimicrobial activity against various strains; nano compound 7 showed potential antimicrobial activity.