@article { ISI:000241306000020, title = {Characterization of nanosized NiZn ferrite powders synthesized by an autocombustion method}, journal = {Materials Chemistry and Physics}, volume = {100}, number = {1}, year = {2006}, month = {NOV}, pages = {98-101}, publisher = {ELSEVIER SCIENCE SA}, type = {Article}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Nanocrystalline Ni0.5Zn0.5Fe2O4 with average particle size of similar to 9 nm has been synthesized by an autocombustion method and characterized by powder XRD, TEM and room temperature magnetic measurements. High room temperature magnetization comparable to that of the bulk material is obtained for the nanosized powders annealed at 800 degrees C, with a maximum particle size of similar to 54 nm. The results show that optimum properties can be achieved for NiZn ferrite powders synthesized by the present autocombustion method and processed at relatively lower temperatures. (c) 2005 Elsevier B.V. All rights reserved.

}, keywords = {Chemical synthesis, Magnetic materials, magnetic properties, Oxides}, issn = {0254-0584}, doi = {10.1016/j.matchemphys.2005.12.012}, author = {Deka, Sasanka and Joy, Pattayil Alias} } @article { ISI:000246042800003, title = {Synthesis and magnetic properties of Mn doped ZnO nanowires}, journal = {Solid State Communications}, volume = {142}, number = {4}, year = {2007}, month = {APR}, pages = {190-194}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Mn doped ZnO nanowires have been synthesized using a simple autocombustion method. The as-synthesized Mn doped ZnO nanowires were characterized by X-ray diffraction and transmission electron microscopy. An increase in the hexagonal lattice parameters of ZnO is observed on increasing the Mn concentration. Optical absorption studies show an increment in the band gap with increasing Mn content, and also give evidence for the presence of Mn2+ ions in tetrahedral sites. All Zn1-xMnxO (0 \<= x \<= 0.25) samples are paramagnetic at room temperature. However, a large increase in the magnetization is observed below 50 K. This behavior, along with the negative value of the Weiss constant obtained from the linear fit to the susceptibility data below room temperature, indicate ferrimagnetic behavior. The origin of ferrimagnetism is likely to be either the intrinsic characteristics of the Mn doped samples, or due to some spinel-type impurity phases present in the samples that could not be detected. (c) 2007 Elsevier Ltd. All rights reserved.

}, keywords = {Combustion synthesis, diluted magnetic semiconductor, magnetic properties, Mn doped ZnO}, issn = {0038-1098}, doi = {10.1016/j.ssc.2007.02.017}, author = {Deka, Sasanka and Joy, Pattayil Alias} } @article { ISI:000261061100016, title = {Magnetic and Mossbauer spectroscopic studies of NiZn ferrite nanoparticles synthesized by a combustion method}, journal = {Hyperfine Interactions}, volume = {183}, number = {1-3}, year = {2008}, month = {APR}, pages = {99-107}, publisher = {SPRINGER}, address = {VAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDS}, abstract = {

The properties of nanocrystalline Ni(0.5)Zn(0.5)Fe(2)O(4) synthesized by an auto-combustion method have been investigated by magnetic measurements and Mossbauer spectroscopy. The as-synthesized single phase nanosized ferrite powder is annealed at different temperatures in the range 673-1,273 K to obtain nanoparticles of different sizes. The powders are characterized by powder X-ray diffraction, vibrating sample magnetometer, transmission electron microscopy and Mossbauer spectroscopy. The as-synthesized powder with average particle size of similar to 9 nm is superparamagnetic. Magnetic transition temperature increases up to 665 K for the nanosized powder as compared to the transition temperature of 548 K for the bulk ferrite. This has been confirmed as due to the abnormal cation distribution, as evidenced from room temperature Mossbauer spectroscopic studies.

}, keywords = {Ferrite, magnetic properties, Mossbauer spectroscopy, Nanoparticles}, issn = {0304-3843}, doi = {10.1007/s10751-008-9736-3}, author = {Sreeja, V. and Vijayanand, S. and Deka, Sasanka and Joy, Pattayil Alias} } @article { ISI:000207804200008, title = {Single step synthesis and properties of M/MFe2O4 and PVDF/M/MFe2O4 (M = Co, Ni) magnetic nanocomposites}, journal = {Science of Advanced Materials}, volume = {1}, number = {3}, year = {2009}, month = {DEC}, pages = {262-268}, publisher = {AMER SCIENTIFIC PUBLISHERS}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

Metal/ferrite nanocomposites (M/MFe2O4; M = Co, Ni), consisting of nanoparticles of a metal and the corresponding metal ferrite, have been synthesized under in situ conditions by a simple and single step process. The metal/ferrite nanocomposites embedded in a polymer matrix have been prepared by a simple hot-pressing method. The performance parameters such as magnetization, coercivity, permeability and dielectric constant of the two- and three-phase nanocomposite systems are compared. The coercivity increases and the permeability decreases with increasing polymer content in the three-phase composite. Enhancement of the dielectric constant is observed at low frequencies.

}, keywords = {Dielectric, Ferrite, magnetic properties, Nanocomposite, Nanocrystalline, permeability}, issn = {1947-2935}, doi = {10.1166/sam.2009.1053}, author = {Deka, Sasanka and Joy, Pattayil Alias and Kumar, A. Pratheep} }