01915nas a2200169 4500008004100000020001800041245010000059210006900159260009600228300001200324520119600336100001801532700002301550700002501573700001901598856012801617 2005 eng d a1-57498-218-400aHigh magnetic aspects of nanosized NiZn ferrite powders synthesized by an autocombustion method0 aHigh magnetic aspects of nanosized NiZn ferrite powders synthesi aSan Francisco, CAbAmer Ceramic Soc, 735 Ceramic Place, Westerville, OH 43081-8720 USAcAUG a149-1543 a

Nanocrystalline NiZn ferrite, Ni0.5Zn0.5Fe2O4, having particle size in the range 6-10 mn, has been synthesized by an auto-combustion method. The nanosized ferrite powder formed at a low temperature is annealed at different temperatures in the range 473-1273 K and characterized by X-ray diffraction, vibrating sample magnetometry, Mossbauer spectroscopy, transmission electron microscopy and scanning electron microscopy. Magnetic transition temperature broadening up to 773 K is observed for the nanosized sample, compared to the T-c = 563 K for the bulk material. Critical particle diameter (D-c) is found to be similar to 40 nm at which maximum coercivity is obtained for the powder sample annealed at 973 K. Similarly, high room temperature magnetization, comparable to that of the bulk material, is obtained for the powders annealed at 1073 K, with a maximum particle size of similar to 50 nm. Very little grain growth is observed for the powders annealed above 1073 K. The results show that, optimum magnetic properties can be achieved for fine particle NiZn ferrite powders synthesized by a low-temperature auto-combustion method and processed at relatively lower temperatures.

1 aDeka, Sasanka1 aDate, Sadgopal, K.1 aJoy, Pattayil, Alias1 aSoohoo, R., F. uhttps://library.ncl.res.in/content/high-magnetic-aspects-nanosized-nizn-ferrite-powders-synthesized-autocombustion-method-001081nas a2200205 4500008004100000022001400041245011600055210006900171260008400240300001200324490000700336520024600343100002600589700002800615700002100643700002500664700002500689700002900714856013200743 2008 eng d a0366-702200aHighly active nanostructured Co3O4 catalyst with tunable selectivity for liquid phase air oxidation of p-cresol0 aHighly active nanostructured Co3O4 catalyst with tunable selecti a1-5 KANDA-SURUGADAI CHIYODA-KU, TOKYO, 101-8307, JAPANbCHEMICAL SOC JAPANcMAR a310-3110 v373 a

This is a first report of highly efficient heterogeneous nanostructured Co3O4 catalyst (6-8 nm) having high surface area (95 m(2)/g) developed for selective liquid phase air oxidation of p-cresol under atmospheric pressure conditions.

1 aKshirsagar, Vikas, S.1 aVijayanand, Subramanian1 aPotdar, Hari, S.1 aJoy, Pattayil, Alias1 aPatil, Kashinath, R.1 aRode, Chandrashekhar, V. uhttps://library.ncl.res.in/content/highly-active-nanostructured-co3o4-catalyst-tunable-selectivity-liquid-phase-air-oxidation-001483nas a2200157 4500008004100000022001400041245008800055210006900143260012500212300001100337490000700348520080200355100002101157700002501178856012201203 2010 eng d a0003-695100aHigh room temperature ferromagnetic moment of Ho substituted nanocrystalline BiFeO30 aHigh room temperature ferromagnetic moment of Ho substituted nan aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScOCT a1625040 v973 a

Magnetic properties of trivalent rare-earth ion substituted nanocrystalline BiFeO3 have been studied for the compositions Bi0.875R0.125FeO3 (R=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb). All compositions show ferromagnetic characteristics at room temperature, with enhanced magnetization after substitution. Very high magnetization (at 6 T), almost three times that of the unsubstituted composition, is observed for R=Ho, and highest remnant magnetization is obtained for R=Nd and Sm. The magnetic transition temperature is increased by similar to 20 K for R=La. The results show that it is possible to tune the magnetic characteristics of the nanocrystalline multiferroic BiFeO3 by the choice of the rare-earth ion. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3502481]

1 aThakuria, Pankaj1 aJoy, Pattayil, Alias uhttps://library.ncl.res.in/content/high-room-temperature-ferromagnetic-moment-ho-substituted-nanocrystalline-bifeo3-001979nas a2200265 4500008004100000022001400041245007500055210006900130260007300199300001000272490000700282520111500289653001401404653001901418653001001437653003001447653000801477653000801485100001901493700001801512700002801530700002501558700002101583856010901604 2010 eng d a0039-914000aHighly sensitive and fast responding CO sensor based on Co3O4 nanorods0 aHighly sensitive and fast responding CO sensor based on Co3O4 na aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR a37-430 v813 a

Co3O4 nanorods (diameters similar to 6-8 nm and lengths similar to 20-30 nm) were synthesized for the first time through a simple co-precipitation/digestion method by calcination of cobalt hydroxyl carbonate in air and their CO gas sensing properties were investigated. The Co3O4 nanorods exhibited outstanding gas sensing characteristics such as, higher gas response (similar to 6.55-50 ppm CO gas at 250 degrees C), extremely rapid response (similar to 3-4s), fast recovery (similar to 5-6s), excellent repeatability, good selectivity and lower operating temperature (similar to 250 degrees C). Furthermore, the Co3O4 nanorods are able to detect up to 5 ppm for CO with reasonable sensitivity (similar to 3.32) at an operating temperature 250 degrees C and they can be reliably used to monitor the concentration of CO over the range (5-50 ppm). The experimental results clearly demonstrate the potential of using the Co3O4 nanorods as sensing material in the fabrication of CO sensors. Plausible CO sensing mechanism of the Co3O4 nanorods is also discussed. (C) 2009 Elsevier B.V. All rights reserved.

10aCO sensor10aCo3O4 nanorods10aHRTEM10aSemiconductor gas sensors10aXPS10aXRD1 aPatil, Dewyani1 aPatil, Pradip1 aSubramanian, Vijayanand1 aJoy, Pattayil, Alias1 aPotdar, Hari, S. uhttps://library.ncl.res.in/content/highly-sensitive-and-fast-responding-co-sensor-based-co3o4-nanorods-001459nas a2200157 4500008004100000022001400041245012400055210006900179260012500248300001100373490000800384520073600392100002801128700002501156856012001181 2012 eng d a0003-695100aHigh magnetostriction and coupling coefficient for sintered cobalt ferrite derived from superparamagnetic nanoparticles0 aHigh magnetostriction and coupling coefficient for sintered coba aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScAUG a0724050 v1013 a

High magnetostriction (lambda) and coupling coefficient (d lambda/dH) of 315 ppm and 1.97 x 10(-9) A(-1) m, respectively, are obtained at room temperature for sintered cobalt ferrite derived from nanocrystalline powders. Also, the powder was compacted at a low pressure of 8 MPa and sintered for a short duration of 10 min at 1450 degrees C. Magnetic annealing at 300 degrees C in a field of 0.5 T for 30 min further enhanced the magnetostriction coefficient to 345 ppm with a higher coupling coefficient 2.12 x 10(-9) A(-1)m. The magnetic field above which maximum magnetostriction is observed is reduced by almost half after magnetic annealing. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4745922]

1 aMohaideen, Kamal, Khaja1 aJoy, Pattayil, Alias uhttps://library.ncl.res.in/content/high-magnetostriction-and-coupling-coefficient-sintered-cobalt-ferrite-derived-001798nas a2200217 4500008004100000022001400041245014400055210006900199260007300268300001400341490000700355520092600362653001901288653002901307653002101336653002001357653002001377100002801397700002501425856013001450 2013 eng d a1567-173900aHigh magnetostriction coefficient of Mn substituted cobalt ferrite sintered from nanocrystalline powders and after magnetic field annealing0 aHigh magnetostriction coefficient of Mn substituted cobalt ferri aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT a1697-17010 v133 a

Magnetostriction characteristics of Mn substituted cobalt ferrite, CoFe2-xMnxO4 (0 <= x <= 0.3), sintered from nanocrystalline powders of average particle size of similar to 4 nm have been studied. Larger value of magnetostriction at lower magnetic field is achieved after substitution of Mn for Fe. The maximum value of magnetostriction coefficient is not much affected and the slope of the magnetostriction is increased with increasing Mn content. Higher maximum value of magnetostriction coefficient (lambda) of 234 ppm comparable to that of the unsubstituted composition with larger strain derivative (d lambda/dH) is obtained for x = 0.2 in CoFe2-xMnxO4. The magnetostriction coefficient is increased to 262 ppm with further enhancement in the strain derivative after annealing the sintered compact at 300 degrees C in a magnetic field of 400 kA/m for 30 min. (C) 2013 Elsevier B.V. All rights reserved.

10aCobalt ferrite10aMagnetic field annealing10aMagnetostriction10aMn substitution10aNanocrystalline1 aMohaideen, Kamal, Khaja1 aJoy, Pattayil, Alias uhttps://library.ncl.res.in/content/high-magnetostriction-coefficient-mn-substituted-cobalt-ferrite-sintered-nanocrystalline-001776nas a2200193 4500008004100000022001400041245011300055210006900168260007300237300001200310490000800322520100800330653001901338653002101357653002401378100002801402700002501430856012701455 2014 eng d a0304-885300aHigh magnetostriction parameters for low-temperature sintered cobalt ferrite obtained by two-stage sintering0 aHigh magnetostriction parameters for lowtemperature sintered cob aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC a121-1290 v3713 a

From the studies on the magnetostriction characteristics of two-stage sintered polycrystalline CoFe2O4 made from nanocrystalline powders, it is found that two-stage sintering at low temperatures is very effective for enhancing the density and for attaining higher magnetostriction coefficient. Magnetostriction coefficient and strain derivative are further enhanced by magnetic field annealing and relatively larger enhancement in the magnetostriction parameters is obtained for the samples sintered at lower temperatures, after magnetic annealing, despite the fact that samples sintered at higher temperatures show larger magnetostriction coefficients before annealing. A high magnetostriction coefficient of similar to 380 ppm is obtained after field annealing for the sample sintered at 1100 degrees C, below a magnetic field of 400 kA/m, which is the highest value so far reported at low magnetic fields for sintered polycrystalline cobalt ferrite. (C) 2014 Elsevier B.V. All rights reserved.

10aCobalt ferrite10aMagnetostriction10aTwo-stage sintering1 aMohaideen, Kamal, Khaja1 aJoy, Pattayil, Alias uhttps://library.ncl.res.in/content/high-magnetostriction-parameters-low-temperature-sintered-cobalt-ferrite-obtained-two-0