@article { ISI:000232341900001, title = {Surface disorder in c-Si induced by swift heavy ions}, journal = {Radiation Effects and Defects in Solids}, volume = {160}, number = {6}, year = {2005}, month = {JUN}, pages = {207-218}, publisher = {TAYLOR \& FRANCIS LTD}, address = {4 PARK SQUARE, MILTON PARK, ABINGDON OX14 4RN, OXON, ENGLAND}, abstract = {

The disorders induced in crystalline silicon (c-Si) through the process of electronic energy loss in the swift heavy ion irradiation were investigated. A number of silicon \<100\> samples were irradiated with 65 MeV oxygen ions at different fluences, 1x10(13) to 1.5x10(14) ions/cm(2), and characterized by the Raman spectroscopy, the optical reflectivity, the X-ray reflectivity, the atomic force microscopy (AFM) and the X-ray diffraction (XRD) techniques. The intensity, redshift, phonon coherence length and asymmetric broadening associated with the Raman peaks reveal that stressed and disordered lattice zones are produced in the surface region of the irradiated silicon. The average crystallite size, obtained by analyzing Raman spectrum with the phonon confinement model, was very large in the virgin silicon but decreased to \<100 nm dimension in the ion irradiated silicon. The results of the X-ray reflectivity, AFM and optical reflectivity of 200-700 nm radiation indicate that the roughness of the silicon surface has enhanced substantially after ion irradiation. The diffusion of oxygen in silicon surface during ion irradiation is evident from the oscillation in the X-ray reflectivity spectrum and the sharp decrease in the reflectivity of 200-400 nm radiation. The rise in temperature, estimated from the heat spike model, was high enough to melt the local silicon surface. The results of XRD indicate that lattice defects have been induced and a new plane \<211\> has been formed in the silicon \<100\> after ion irradiation. The results of the present study show that the energy deposited in crystalline silicon through the process of electronic energy loss similar to 0.944 keV/nm per ion is sufficient to induce disorders of appreciable magnitude in the silicon surface even at a fluence of similar to 10(13) ions/cm(2).

}, keywords = {AFM, crystalline silicon, ion irradiation, optical and X-ray reflectivity, Raman, XRD}, issn = {1042-0150}, doi = {10.1080/10420150500275288}, author = {Bogle, Kashinath A. and Gokhale, Suresh P. and Bhoraskar, Vasant N.} } @article { ISI:000252408000048, title = {Synthesis of LSMO at low temperature by novel hydroxide precursor technique}, journal = {Materials Letters}, volume = {62}, number = {3}, year = {2008}, month = {FEB}, pages = {527-529}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

A novel technique of mixing individual hydroxide is employed to prepare La0.65Sr0.35MnO3 (LSMO) at low temperature. Freshly prepared lanthanum and manganese hydroxides are mixed thoroughly with strontium hydroxide in stoichiometric ratio and heated at different temperatures ranging from 100 to 500 degrees C for 6 h. At 500 degrees C, formation of La0.65Sr0.35MnO3 was confirmed by the X-ray diffraction studies (XRD). This is the lowest temperature so far reported in the literature. The particle size and morphology were investigated by scanning electron microscopy (SEM). (c) 2007 Elsevier B.V. All rights reserved.

}, keywords = {Ceramics, Electron microscopy, La0.65Sr0.35MnO3, Oxides, Precipitation, X-ray diffraction}, issn = {0167-577X}, doi = {10.1016/j.matlet.2007.05.077}, author = {Gupta, U. N. and Muthurajan, H. and Kumar, H. H. and Rao, N. Koteswara and Gokhale, Suresh P. and Ravi, V.} } @article { ISI:000316024500022, title = {Synthesis of low coercive BaFe12O19 hexaferrite for microwave applications in low-temperature cofired ceramic}, journal = {Journal of Electronic Materials}, volume = {42}, number = {4}, year = {2013}, month = {APR}, pages = {761-768}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Polycrystalline M-type barium hexaferrite (BaFe12O19) samples have been synthesized by solution combustion route at different pH and calcination conditions in order to reduce the coercivity for microwave applications in low-temperature cofired ceramic (LTCC) substrates. Structural, morphological, and magnetic properties of BaFe12O19 were studied by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectroscopy, vibrating sample magnetometry (VSM), and Mossbauer spectroscopy. The formation of a single-phase hexagonal structure was confirmed by XRD. The Raman spectra reveal all characteristic peaks of BaFe12O19, illustrating the phase purity and crystal lattice symmetry of the synthesized material. Mossbauer spectra illustrate the existence of Fe3+ cations at all five crystallographic lattice sites. The microstructural features observed by FESEM disclose the growth of nanoregime particles into hexagonal platelet particles after calcination at temperatures from 800A degrees C to 1200A degrees C. The VSM results show a lower coercivity (1350 Oe to 3500 Oe) together with reasonably high saturation magnetization (55 emu/g to 60 emu/g) and a high bulk resistivity (\> 10(9) Omega-cm) at room temperature. The dependence of magnetic and electrical properties on the preparation and processing conditions is also discussed.

}, keywords = {Barium hexaferrite, coercivity, LTCC, Mossbauer spectroscopy, Raman spectroscopy}, issn = {0361-5235}, doi = {10.1007/s11664-012-2398-6}, author = {Rane, Vivek A. and Meena, Sher Singh and Gokhale, Suresh P. and Yusuf, S. M. and Phatak, Girish J. and Date, Sadgopal K.} }