01891nas a2200265 4500008004100000022001400041245007000055210006900125260009500194300001400289490000600303520100600309653001701315653001001332653002601342653002401368653001801392100001701410700002701427700001501454700001701469700001701486700001901503856010301522 2008 eng d a1533-488000aStructure and microbial synthesis of sub-10 nm Bi2O3 nanocrystals0 aStructure and microbial synthesis of sub10 nm Bi2O3 nanocrystals a25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USAbAMER SCIENTIFIC PUBLISHERScAUG a3909-39130 v83 a

After the advent of novel chemical and microbial techniques, providing control over grain size and shape of the nanomaterials, several binary-oxide materials have been explored in size less than 10 nm for their tunable physical properties. Bi2O3 nanoparticles have also redrawn attention due to their excellent properties, mostly as optoelectronic material. Here, we report the room-temperature biosynthesis of Bi2O3 nanoparticles in a size range of 5-8 nm by extra-cellularly challenging the plant pathogenic fungus-Fusarium oxysporum with the bismuth nitrate as precursor. The as-synthesized particle-surfaces are inherently functionalized by a robust layer of proteins which provides them very good stability in the aqueous medium. Structural investigation using selected area electron diffraction, high resolution transmission electron microscopy and powder XRD shows that particles are almost perfectly single crystalline and primarily crystallize in alpha-phase with monoclinic structure.

10aBiosynthesis10afungi10aHigh Refractive Index10aHigh Resolution TEM10aNanoparticles1 aUddin, Imran1 aAdyanthaya, Suguna, D.1 aSyed, Asad1 aSelvaraj, K.1 aAhmad, Absar1 aPoddar, Pankaj uhttp://library.ncl.res.in/content/structure-and-microbial-synthesis-sub-10-nm-bi2o3-nanocrystals-002881nas a2200181 4500008004100000022001400041245013600055210006900191260007100260300001400331490000800345520213500353100002002488700001402508700002702522700001902549856013102568 2011 eng d a1932-744700aSurface effects on morin transition, exchange bias, and enchanced spin reorientation in chemically synthesized DyFeO3 nanoparticles0 aSurface effects on morin transition exchange bias and enchanced  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB a2954-29600 v1153 a

A giant linear magnetoelectric effect was observed by Y. Tokura's group recently in multiferroic DyFeO3, which demands a detailed investigation of its magnetic properties. Additionally, there is little information on the changes of chemical and physical properties of these materials with the reduction in particle size in spite of the potential applications of these materials nanoscale devices. As the wet-chemical synthesis of these materials in nanosize and getting a control over crystallinity and stoichiometry is nontrivial and poses a serious challenge prohibiting the study of their size-dependent properties. Here, we report the synthesis of DyFeO3 nanoparticles using a surfactantless hydrothermal method with a detailed magnetic property measurement. The as-synthesized DyFeO3 nanoparticles showed excellent crystallinitywith average particle size in the range 50-60 nm. The structural analysis indicated that they are of a distorted orthorhombic pervoslcite crystal structure. Detailed dc magnetization measurements in the temperature range of 3-350 K could isolate the presence of Dy3+-Fe3+ and Dy3+-Dy3+ superexchange interactions, which showed up as spin reorientation transitions in various temperature regions due to the differing magnitude of their interactions resulting in continuous rotation of antiferromagnetic component of Fe3+ spins with cooling of the sample. Nanosized DyFeO3 showed spin-reorientation transitions near 315 and 70K due to the Dy3+-Fe3+ interaction accompanied with an opening up of the hysteresis loop followed by antiferromagnetic ordering around 4 K due to a possible Dy3+-Dy3+ interaction. We also observed significant effect of the particle size reduction on the magnetic properties. The main effects seen. by us were in terms of (1) pronounced spontaneous spin reorientation transitions, (2) the absence of Morin transition, and (3) presence of temperature-dependent exchange bias in the DyFeO3 nanoparticles. We present a detailed mechanism to explain these features based on the interplay of Dy3+ and Fe3+ spins as well surface disorder, anisotropy, canting, and so forth.

1 aJaiswal, Adhish1 aDas, Raja1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj uhttp://library.ncl.res.in/content/surface-effects-morin-transition-exchange-bias-and-enchanced-spin-reorientation-chemically-001263nas a2200217 4500008004100000022001400041245005800055210005800113260007400171300001400245490000700259520054300266653001700809653001800826653003000844100002000874700001400894700002700908700001900935856009100954 2011 eng d a1388-076400aSynthesis and optical studies of GdCrO3 nanoparticles0 aSynthesis and optical studies of GdCrO3 nanoparticles aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcMAR a1019-10270 v133 a

{Here we report for the first time, a detailed synthesis mechanism of GdCrO3 nanoparticles using a surfactant-less hydrothermal method. We also report a detailed study of their structural and optical properties. The selected area electron diffraction and powder X-ray diffraction studies of GdCrO3 nanoparticles show pure phase and excellent crystallinity with average particle size around 50-60 nm. The structural analysis indicates a distorted perovskite crystal structure with lattice parameter values of a = 5.3099 +/- A 0.0022

10ahydrothermal10aNanoparticles10aRare earth orthochromites1 aJaiswal, Adhish1 aDas, Raja1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj uhttp://library.ncl.res.in/content/synthesis-and-optical-studies-gdcro3-nanoparticles-002968nas a2200181 4500008004100000022001400041245015200055210006900207260011000276300001400386490000600400520216900406100001702575700002002592700002702612700001902639856012802658 2013 eng d a2046-206900aSurface chemistry and growth mechanism of highly oriented, single crystalline TiO2 nanorods on transparent conducting oxide coated glass substrates0 aSurface chemistry and growth mechanism of highly oriented single aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcNOV a1933-19400 v33 a

The fabrication of one-dimensional (1D) rods or wires of titania in desired crystalline facets is quite exciting due to unique optoelectronic properties. The single crystalline, oriented nanorods directly grown on transparent conducting oxide (TCO) substrates are finding a lot of interest in solar photovoltaics and several other optoelectronic devices due to enhanced electron transport and lower exciton recombination rates. However, the growth of desired crystalline facets of highly oriented, single crystalline nanorods on different substrates and understanding the interplay between the surface chemistry and growth mechanism still remain a non-trivial and challenging task. Here, for the first time, the kinetically controlled growth of the (310) facet of TiO2 nanorods on fluorine-doped tin oxide (FTO) coated glass substrate has been reported which is in contrast to the previously reported (002) faceted TiO2 nanorods. In addition to this, the growth of (110) facet TiO2 nanorods using amorphous fluorine doped silicon oxide (FSO) as a substrate is also demonstrated. In this paper, it is shown that two different faceted TiO2 nanorods can be synthesized following same synthetic condition by varying only the material properties of the substrate. To investigate the role of substrate chemistry on the morphology and single crystallinity of TiO2 nanorods, electron microscopy, XPS and contact angle measurements have been done. The results clearly indicate an important link between the surface chemistry and morphology of TiO2 nanorods. It can be assumed that there is a role of OH- and water groups which are responsible for the growth of plane (110) which has less surface energy. The observation of (310) facet is quite surprising and can be explained based on FTO crystallinity. It is possible to tune the diameter of the titania nanorods by further coating the FTO substrate with a thin gold layer due to increase in the hydrophilicity of the substrate. Finally, a light to electricity conversion efficiency of 2.5% could be achieved by using vertically grown titania nanorods on FTO as the photoanode in a dye sensitized solar cell (DSSC).

1 aSadhu, Subha1 aJaiswal, Adhish1 aAdyanthaya, Suguna, D.1 aPoddar, Pankaj uhttp://library.ncl.res.in/content/surface-chemistry-and-growth-mechanism-highly-oriented-single-crystalline-tio2-nanorods-0