01793nas a2200253   4500008004100000022001400041245006300055210006300118260009500181300001400276490000600290520093200296653002201228653002101250653002401271653003001295100001601325700001501341700002401356700003001380700001601410700001701426856009601443       2008                        eng d  a1533-488000aStatic and dynamic magnetic properties of Co nanoparticles0 aStatic and dynamic magnetic properties of Co nanoparticles  a25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USAbAMER SCIENTIFIC PUBLISHERScAUG  a4086-40910 v83 a<p>Co nanoparticles have been synthesized using wet-chemical methods. As-synthesized particles show a sharp low temperature peak in zero-field cooled (ZFC) magnetization well below the blocking transition temperature and this feature is associated with surface spin disorder. We have investigated the dynamic magnetic properties of Co using ac susceptibility and resonant RF transverse susceptibility (TS). We also studied the memory and relaxation effects in these nanoparticle systems. From these measurements we show a typical blocking behavior of an assembly of superparamagnetic nanoparticles with a wide distribution of blocking temperatures. The transverse susceptibility measurements on these particles show the presence of anisotropy even above the blocking temperature. The role of surface anisotropy and the size distribution of the particles on the observed memory and magnetic relaxation effects are discussed.</p>10aAc Susceptibility10aCo Nanoparticles10aMagnetic relaxation10aTransverse Susceptibility1 aSrinath, S.1 aPoddar, P.1 aSidhaye, Deepti, S.1 aPrasad, Bhagavatula L. V.1 aGass, James1 aSrikanth, H.  uhttp://library.ncl.res.in/content/static-and-dynamic-magnetic-properties-co-nanoparticles-002305nas a2200205   4500008004100000022001400041245009900055210006900154260011000223300001600333490000600349520151300355100001901868700001501887700001901902700001501921700001501936700001801951856013001969       2015                        eng d  a2046-206900aSpin-coatable, photopatternable magnetic nanocomposite thin films for MEMS device applications0 aSpincoatable photopatternable magnetic nanocomposite thin films   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcOCT  a85741-857470 v53 a<p>Magnetic nanomaterials' (especially metals) air stability and compatibility with standard micro-fabrication technologies are often a concern for development of MEMS-based magnetic devices. In this paper, we report an air-stable, photo-patternable and spin-coatable magnetic thin film preparation process for MEMS applications. This magnetic nanocomposite thin film was prepared by incorporating carbon capped ferromagnetic cobalt nanoparticles of dimension 20-80 nm into the SU-8 matrix. TEM, XRD and EDAX analyses were done, to investigate the crystal structure, dispersion and phase stability of the films. The SQUID magnetometry and MFM measurements of the film confirmed its magnetic response at room temperature and the retention of its magnetic properties over a period of time. The material compatibility for MEMS device applications was demonstrated through fabrication of a suspended circular membrane of radius similar to 250 mu m, having four U-shaped beams, of dimension similar to 270 x 50 mu m each. Three conventional lithography steps and a sacrificial release layer of similar to 1 mm thick oxide was used for the fabrication. The membrane was characterized by evaluating its spring constant and resonant frequency. The spring constant and resonant frequencies were estimated to be similar to 4.2 N m(-1) and similar to 29 kHz respectively. Finally, we demonstrated the actuation of the magnetic membrane by an off-chip generated magnetic field, for its possible use as a MEMS device.</p>1 aKandpal, Manoj1 aSharan, C.1 aPalaparthy, V.1 aTiwary, N.1 aPoddar, P.1 aRao, Ramgopal  uhttp://library.ncl.res.in/content/spin-coatable-photopatternable-magnetic-nanocomposite-thin-films-mems-device-applications-002808nas a2200181   4500008004100000245016000041210006900201260000800270300001400278490000700292520212300299100001502422700001602437700001902453700001202472700001502484856012702499       2017                        eng d00aSurface disordered rutile TiO2-graphene quantum dot hybrids: a new multifunctional material with superior photocatalytic and biofilm eradication properties0 aSurface disordered rutile TiO2graphene quantum dot hybrids a new  cAPR  a2642-26570 v413 aThe controlled introduction of defects in semiconductors has contributed to the development of electronic devices and technologies. Recently, chemical control over defects, formation of new hybrid materials and multifunctional nanostructures have been sought in energy, health, and environment related technologies. Surface-disordered anatase-TiO2 has received wide attention due to its exceptional photocatalytic performance. Herein, we demonstrate, for the first time, a one-step aqueous-phase synthesis of a surface-disordered rutile TiO2-graphene quantum dot (TG) hybrid material. The TG-hybrid is a rutile-TiO2 matrix in which homogeneous in situ insertion of GQDs occurs during the growth of the TiO2 particles. The TG-hybrid material showed superior photocatalytic performance with similar to 98% solar light driven photo-degradation of methylene blue (MB) dye within 6 min and similar to 86% of rhodamine-B (RhB) within 4 min which is much better than the photocatalytic performance shown by the rutile-TiO2 (similar to 30% and similar to 20%, respectively) and GQDs (similar to 15% and similar to 8%, respectively), themselves. Moreover, the TG-hybrid also showed enhanced toxicity to Gram-positive (S. aureus) as well as Gram-negative (E. coli, P. aeruginosa) bacterial cells. The growth-curves of E. coli cells, after incubating them with increasing concentrations of the TG-hybrid, showed that the TG-hybrid could effectively inhibit the growth of E. coli cells at a concentration of 60 mu g mL(-1). The effect of UV-light exposure on the bacterial-biofilm disruption by the TG-hybrid material was also investigated. It was observed that in the presence of UV-light, the biofilm disruption done by the TG-hybrid was larger in comparison to the TiO2 and GQDs alone, under the same conditions. The increase in the formation of reactive oxygen species (ROS) in the presence of sunlight for the TG-hybrid may be the reason behind its superior antibacterial and biofilm eradication properties. We believe that the TG-hybrid material will have applications in energy, health and environment related technologies.1 aBiswas, A.1 aSalunke, G.1 aKhandelwal, P.1 aDas, R.1 aPoddar, P.  uhttp://library.ncl.res.in/content/surface-disordered-rutile-tio2-graphene-quantum-dot-hybrids-new-multifunctional-material