01967nas a2200241 4500008004100000022001400041245008400055210006900139260006900208300001200277490000800289520111400297653001301411653001501424653005501439100002001494700001901514700002001533700001801553700001701571700002201588856011501610 2009 eng d a0925-838800aGas sensing properties of magnesium ferrite prepared by co-precipitation method0 aGas sensing properties of magnesium ferrite prepared by coprecip aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcNOV a270-2720 v4883 a

Polycrystalline magnesium ferrite (MgFe(2)O(4)) was prepared by the co-precipitation method. The synthesized compound was characterized for their phase and morphology by X-ray diffraction and scanning electron microscopy, respectively. Conductance responses of the (MgFe(2)O(4)) were measured towards gases like hydrogen sulfide (H(2)S), liquefied petroleum gas (LPG), ethanol vapors (C(2)H(5)OH), SO(x), H(2), NO(x), NH(3), methanol, acetone and petrol. The gas sensing characterstics were obtained by measuring the sensitivity as a function of various controlling factors like operating temperatures and concentrations of gases. It was found that the sensor exhibited various responses towards these gases at different operating temperatures. Furthermore; the MgFe(2)O(4) based sensor exhibited a fast response and a good recovery towards petrol at temperature 250 degrees C. The results of the response towards petrol reveal that (MgFe(2)O(4)) synthesized by a simple co-precipitation method, would be a suitable material for the fabrication of the petrol sensor. (C) 2009 Published by Elsevier B.V.

10aFerrites10aGas sensor10aX-ray diffraction and scanning electron microscopy1 aHankare, P., P.1 aJadhav, S., D.1 aSankpal, U., B.1 aPatil, R., P.1 aSasikala, R.1 aMulla, Imtiaz, S. uhttps://library.ncl.res.in/content/gas-sensing-properties-magnesium-ferrite-prepared-co-precipitation-method-001866nas a2200217 4500008004100000022001400041245006500055210006400120260009900184300001400283490000700297520112100304653001301425653001701438653001101455653001201466100002501478700002401503700002201527856009901549 2009 eng d a0272-884200aNanostructured nickel ferrite: a liquid petroleum gas sensor0 aNanostructured nickel ferrite a liquid petroleum gas sensor aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcJUL a1793-17970 v353 a

The present investigation deals with the synthesis of nanostructured nickel ferrite (NiFe(2)O(4)) and their liquid petroleum gas-sensing characteristics. The 15-20 nm size nickel ferrite has been synthesized at 700 degrees C by a simple molten-salt route using sodium chloride as grain growth inhibitor. These nanoparticles exhibit significantly high response towards liquid petroleum gas (LPG) in comparison with ethanol vapor, hydrogen sulfide, ammonia and hydrogen. The gas response towards various gases at their 200 ppm concentrations is investigated at 200-450 degrees C. Different characterization techniques have been employed, such as differential thermal analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HRTEM) to study the crystallite size, structure and morphology. The results suggest possibility of utilization of the nanostructured nickel ferrite, without addition of any precious metal ion, as the LPG detector. (c) 2008 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

10aFerrites10ananomaterial10aSensor10aSpinels1 aDarshane, Sonali, L.1 aSuryavanshi, S., S.1 aMulla, Imtiaz, S. uhttps://library.ncl.res.in/content/nanostructured-nickel-ferrite-liquid-petroleum-gas-sensor-001985nas a2200265 4500008004100000022001400041245014300055210006900198260006900267300001200336490000800348520101100356653002301367653001301390653001001403653003301413653002201446100002001468700001901488700002001507700002401527700002101551700002101572856012601593 2009 eng d a0925-838800aSynthesis, characterization and effect of sintering temperature on magnetic properties of MgNi ferrite prepared by co-precipitation method0 aSynthesis characterization and effect of sintering temperature o aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcMAY a926-9290 v4753 a

Mixed MgNi ferrites with composition Mg(0.5)Ni(0.5)Fe(2)O(4) where the mole fraction for Ni (x = 0, 0.25, 0.75, 0.5 and 1) were prepared by following co-precipitation method at temperature 110 degrees C and maintaining a pH of solution equal to 9.5 enable to achieve large particle surface area. The resultant materials obtained in powder form were sintered at different temperatures. Thermogravimetry (TGA), X-ray diffraction (XRD) and scanning electron microscopy, technique were applied to obtain structural parameters. The XRD patterns reveal the presence of(311) peak as the most intense one. The intensity of XRD peak increases with increase in sintering temperature. The saturation magnetization values showed increasing trend with increase in sintering temperature from 2.37 to 29.76 emu/g. These results along with the analysis of SEM micrographs are interpreted in terms of increase in particle grain size with increase in sintering temperature. (C) 2008 Elsevier B.V. All rights reserved.

10aChemical synthesis10aFerrites10aFT-IR10ascanning electron microscopy10aX-ray diffraction1 aHankare, P., P.1 aJadhav, S., D.1 aSankpal, U., B.1 aChavan, Santosh, S.1 aWaghmare, K., J.1 aChougule, B., K. uhttps://library.ncl.res.in/content/synthesis-characterization-and-effect-sintering-temperature-magnetic-properties-mgni-001900nas a2200289 4500008004100000022001400041245011400055210006900169260007300238300001400311490000800325520088700333653002201220653002401242653001301266653002401279653002201303653002201325100002001347700001801367700002001385700002101405700001701426700002101443700002201464856012401486 2010 eng d a0304-885300aMagnetic, dielectric and complex impedance spectroscopic studies of nanocrystalline Cr substituted Li-ferrite0 aMagnetic dielectric and complex impedance spectroscopic studies  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcSEP a2629-26330 v3223 a

Nanocrystalline Li0.5Fe2.5-xCrxO4 (2.5 <= x >= 0) ferrites were prepared by a sol-gel autocombustion route. X-ray diffraction was employed to confirm the cubic spinel phase formation of the ferrites. The lattice parameter decreases with increase in Cr content. The saturation magnetization, coercivity and remanance were studied as a function of Cr content. The dielectric constant and dielectric loss were measured as a function of frequency in the frequency range 20 Hz-1 MHz. Frequency dependence of dielectric constant shows dielectric dispersion due to the Maxwell-Wagner type of interfacial polarization. In order to understand the conduction mechanism, complex impedance measurements were carried out. The substitution of chromium plays an important role in changing the dielectric and magnetic properties of lithium ferrites. (C) 2010 Published by Elsevier B.V.

10aComplex impedance10adielectric response10aFerrites10aMagnetic hysteresis10aSol-gel synthesis10aX-ray diffraction1 aHankare, P., P.1 aPatil, R., P.1 aSankpal, U., B.1 aGaradkar, K., M.1 aSasikala, R.1 aTripathi, A., K.1 aMulla, Imtiaz, S. uhttps://library.ncl.res.in/content/magnetic-dielectric-and-complex-impedance-spectroscopic-studies-nanocrystalline-cr-003386nas a2200229 4500008004100000245014900041210006900190260000800259300001600267490000600283520252700289653001602816653002102832653001302853653001602866653003002882653003302912100002902945700002802974700003103002856012303033 2024 eng d00aEffect of transition metals (Mn, Co, Ni, and Zn) in size-controlled metal ferrite nanocrystals on the electrocatalytic oxygen evolution reaction0 aEffect of transition metals Mn Co Ni and Zn in sizecontrolled me cJUL a17776-177850 v73 a

Metal ferrite (MFO) M2+Fe2O4 (M2+ = Mn, Co, Ni, and Zn) nanocrystals (NCs) with a controlled size of similar to 4 nm were synthesized using stearic acid as the capping agent via a facile solvothermal method. The as-synthesized MnFe2O4 (MnFO), CoFe2O4 (CoFO), NiFe2O4 (NiFO), and ZnFe2O4 (ZnFO) NCs were characterized by XRD, FT-IR, Raman, XPS, TGA, TEM, and HRTEM analyses. The electrocatalytic oxygen evolution reaction (OER) is significant for future renewable energy to produce pure hydrogen (H-2) fuels through H2O splitting. However, because of the complex proton-coupled multielectron transfer process, it is kinetically quite challenging. Fe-containing transition metal-based electrocatalysts are well studied since it has been observed that Fe has a significant role in enhancing OER activity. It is well-known that the size and shape of the Fe/ferrite-based nanoelectrocatalyst play a vital role in electrocatalysis reactions. However, it is also critical to understand the effect of other earth-abundant and cost-effective transition metal ions (e.g., Mn, Co, Ni, and Zn) combined with Fe/ferrite NC-based OER electrocatalytic reactions while keeping the size of NCs constant and compare their electrocatalytic properties toward the development of advanced nanoelectrocatalysts, which is rarely studied to the best of the authors knowledge. Therefore, herein, the electrocatalytic properties for OER were examined by using the as-synthesized MnFO, CoFO, NiFO, and ZnFO NCs to understand the effect of metal ions (Mn, Co, Ni, and Zn) on the Fe-based nanoelectrocatalysts by keeping the size of the nanoelectrocatalysts constant at similar to 4 nm. Additionally, the influence of different substrates, e.g., carbon paper (CP) and nickel foam (NF), on the electrocatalytic activity of MFO (MnFO, CoFO, NiFO, and ZnFO) NCs was also compared. Interestingly, as an OER nanoelectrocatalyst, the CoFO NCs on the CP substrate show better electrochemical OER activity than other MFO NCs, with a Tafel slope value of 49.4 mV dec(-1), an ECSA of 112 cm(2), and a long-term stability of 24 h, which is comparatively higher than the other as-synthesized MFO NCs. On the other hand, MnFO NCs on the NF substrate show better electrochemical OER activity than the other as-synthesized MFO NCs. Therefore, this work highlights the effect of the substrate and the influence of transition metals, e.g., Mn, Co, Ni, and Zn, on size-controlled Fe-based nanoelectrocatalysts toward developing advanced OER electrocatalysts.

10aCarbonpaper10aelectrocatalysis10aFerrites10aNickel foam10aOxygen Evolution Reaction10aSize-controlled nanocrystals1 aJeyavani, Vijayakrishnan1 aManoj, Shanmugasundaram1 aMukherjee, Shatabdi, Porel uhttps://library.ncl.res.in/content/effect-transition-metals-mn-co-ni-and-zn-size-controlled-metal-ferrite-nanocrystals01738nas a2200241 4500008004100000022001400041245014600055210006900201260000900270300001100279490000800290520089800298653003001196653001301226653002301239653002201262100001701284700001801301700001101319700001901330700001801349856012901367 2024 eng d a0038-109800aUnveiling electronic structure and magnetic properties of AFe2O4 (A = Co, Ni, Zn, and Mg): Synergizing experimentation with DFT investigation0 aUnveiling electronic structure and magnetic properties of AFe2O4 cAPR  a1154590 v3823 a

This study presents the synthesis of nano-crystalline spinel ferrites AFe2O4 (A = Co2+, Ni+2, Zn+2, and Mg+2), through the sol-gel method, yielding crystallite sizes ranging from 12 to 28 nm. The variation in IR and Raman spectra due to M-O-M bonding supports the variation in lattice parameters. The magnetization measurements revealed that CoFe2O4 has a high saturation magnetization of -55 emu/g and coercivity of -1350 Oe, while ZnFe2O4 exhibited saturation magnetization value of -8 emu/g and coercivity of -16 Oe. In addition, the electronic structure calculated using DFT, which corroborated the antiparallel alignment of Fe ions in the tetrahedral and octahedral sites, validating the measured magnetic moments. Notably, the CoFe2O4 ferrite exhibited a higher squareness ratio than other ferrites, signifying its suitability as a magnetic material for audiovideo recording.

10aDensity functional theory10aFerrites10aMagnetic materials10aX-ray diffraction1 aDhaka, Saroj1 aShukla, Aarti1 aGarima1 aPoonia, Kavita1 aKumar, Sudesh uhttps://library.ncl.res.in/content/unveiling-electronic-structure-and-magnetic-properties-afe2o4-co-ni-zn-and-mg-synergizing