@article { ISI:000239426700005, title = {Experimental comparison of the structural, magnetic, electronic, and optical properties of ferromagnetic and paramagnetic polycrystalline Zn1-xCoxO (x=0,0.05,0.1)}, journal = {Physical Review B}, volume = {74}, number = {3}, year = {2006}, month = {JUL}, pages = {Article No. 033201}, publisher = {AMERICAN PHYSICAL SOC}, type = {Article}, address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA}, abstract = {

Ferromagnetism at room temperature is observed in one case whereas paramagnetism down to 12 K is observed in the second case when polycrystalline Zn1-xCoxO is synthesized under almost identical conditions. Identical x-ray diffraction, optical absorption, and x-ray photoelectron spectroscopy results indicate the incorporation of Co2+ ions in the ZnO lattice in both cases. However, electron diffraction studies show the presence of Co metal impurities in the ferromagnetic samples, indicating that pure Co doped ZnO is not likely to be ferromagnetic.

}, issn = {1098-0121}, doi = {10.1103/PhysRevB.74.033201}, author = {Deka, Sasanka and Pasricha, Renu and Joy, Pattayil Alias} } @article { ISI:000245599400011, title = {Effect of halogen addition to monolayer protected gold nanoparticles}, journal = {Journal of Materials Chemistry}, volume = {17}, number = {16}, year = {2007}, month = {FEB}, pages = {1614-1619}, publisher = {ROYAL SOC CHEMISTRY}, type = {Article}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

The effects of N-halosuccinimide and halogen addition to monolayer protected gold nanoparticles (Au NPs) dispersed in organic media are described. Contrary to the expectation that nanoparticles dispersed in organic media are stable against aggregation, N-iodosuccinimide addition induced aggregation of octadecylamine capped gold nanoparticles in chloroform or toluene. It was observed that even KI and CuI addition could bring about the aggregation though they are very sparingly soluble in organic solvents. It was also found that even molecular iodine could bring about the above mentioned aggregation. Interestingly, when CuI is used the aggregated structures readily convert to very thin flat nanostructures upon exposure to an electron beam or UV irradiation. In fact when the aggregation is induced by the addition of KI or N-iodosuccinamide we do not see the flattening of the aggregated structures exemplifying the important role of Cu ions in making these flat structures.

}, issn = {0959-9428}, doi = {10.1039/b614934k}, author = {Singh, Sanjay and Pasricha, Renu and Bhatta, Umananda M. and Satyam, P. V. and Sastry, Murali and Bhagavatula L. V. Prasad} } @article { ISI:000340292800014, title = {Extracellular biosynthesis of metal sulfide nanoparticles using the fungus fusarium oxysporum}, journal = {Current Nanoscience}, volume = {10}, number = {4}, year = {2014}, month = {JUL}, pages = {588-595}, publisher = {BENTHAM SCIENCE PUBL LTD}, address = {EXECUTIVE STE Y-2, PO BOX 7917, SAIF ZONE, 1200 BR SHARJAH, U ARAB EMIRATES}, abstract = {

The development of reliable, eco-friendly processes for the synthesis of nanomaterials is an important aspect of nanotechnology. One approach that shows immense potential is based on the biosynthesis of nanoparticles using microorganisms such as bacteria. In this report, we demonstrate the extracellular biosynthesis and complete characterization of metal sulfide (PbS, ZnS, MnS and NiS) nanoparticles using fungus, Fusarium oxysporum. We observed that the exposure of aqueous solution of 1 mM metal sulfate to fungus Fusarium oxysporum resulted in the formation of highly stable technologically important metal sulfide semiconductor nanoparticles. Fusarium oxysporum synthesizes lead sulfide and zinc sulfide nanoparticles of fractal type structure whereas manganese sulfide and nickel sulfide nanoparticles are of variable polydispersed morphology. The variable morphology may be due to the dissimilar interaction of metal sulfide nanoparticles with capping proteins secreted by the fungus in solution. The nanoparticles solution is found to be extremely stable with little evidence of aggregation even after a month of storage. The long term stability of the nanoparticles is due to the proteins secreted by fungus in the nanoparticle solution which bind to the surface of the nanoparticles and thus prevent aggregation.

}, keywords = {Biosynthesis, enzymes, fungi, metal sulfide, Nanoparticles}, issn = {1573-4137}, author = {Senapati, Satyajyoti and Syed, Asad and Khan, Shadab and Pasricha, Renu and Khan, Mohammad Islam and Kumar, Rajiv and Ahmad, Absar} }