A simple chemical route is developed to generate maghemite (γ-Fe2O3) nano-particles, dispersed in... more A simple chemical route is developed to generate maghemite (γ-Fe2O3) nano-particles, dispersed in organic solvents via a thermal decomposition of an ironhydroxy oleate precursor. An ironhydroxy oleate precursor was generated by chemical reaction of mixed ...
... Publishing Company SOLAR SELECTIVE COPPER-BLACK LAYERS BY AN ANODIC OXW TTON PROCESS* HS POTD... more ... Publishing Company SOLAR SELECTIVE COPPER-BLACK LAYERS BY AN ANODIC OXW TTON PROCESS* HS POTDAR, Neela PAVASKAR, Anjana MITRA and APB SINHA Nationai ... asa/e (Kl 300 0.95 0.2 4.75 373 0.95 0.34 2.794 100 9-07mA /cm2 80 9~67mA /cm2 w U zc ...
ABSTRACT Ferroelectric BiFeO(3) (BFO) nanoparticles deposited on epitaxial substrates of SrRuO(3)... more ABSTRACT Ferroelectric BiFeO(3) (BFO) nanoparticles deposited on epitaxial substrates of SrRuO(3) (SRO) and La(1-x)Sr(x)MnO(3) (LSMO) were studied using band excitation piezoresponse spectroscopy (BEPS), piezoresponse force microscopy (PFM), and ferromagnetic resonance (FMR). BEPS confirms that the nanoparticles are ferroelectric in nature. Switching behavior of nanoparticle clusters were studied and showed evidence for inhomogeneous switching. The dimensionality of domains within nanoparticles was found to be fractal in nature, with a dimensionality constant of similar to 1.4, on par with ferroelectric BFO thin-films under 100 nm in thickness. Ferromagnetic resonance studies indicate BFO nanoparticles only weakly affect the magnetic response of LSMO. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3671392]
A simple one-step cation-exchange reaction between the stoichiometric solutions of ammonium titan... more A simple one-step cation-exchange reaction between the stoichiometric solutions of ammonium titanyl oxalate (ATO) and barium hydroxide+ strontium nitrate at room temperature (RT) is investigated successfully for the quantitative precipitation of barium ...
A simple citrate gel route was adopted for the preparation of bismuth titanate (Bi4Ti3O12) powder... more A simple citrate gel route was adopted for the preparation of bismuth titanate (Bi4Ti3O12) powders. Stoichiometric quantities of BiCl3 and TiOCl2 were mixed with required amount of citric acid, and the mixture was heated on a water bath. This leads to formation of gel, which was decomposed at 673K. Formation of bismuth titanate was observed on calcining powders at 973K
ABSTRACT Submicron-sized, spherical, stoichiometric strontium substituted barium titanate: Ba0.75... more ABSTRACT Submicron-sized, spherical, stoichiometric strontium substituted barium titanate: Ba0.75Sr0.25TiO3 (BST) powders are prepared by microwave-hydrothermal (MH) route under the MH conditions of 200 °C, 200 psi, and 30 min in strongly alkaline conditions (pH>12) using potassium titanyl oxalate (KTO) and nitrates of Ba and Sr as the starting precursors and KOH as the mineralizer. The characterization studies by XRD, XRF and SEM indicated that stoichiometric cubic BST powders (a0=3.992 Å) were obtained by adjusting MH conditions mentioned earlier and keeping the (Ba+Sr)/Ti ratio in starting solution slightly in excess (∼1.06).
ABSTRACT Synthesis of La0.5Ba0.5MnO3 powder by microwave-hydrothermal (MH) accelerated solid stat... more ABSTRACT Synthesis of La0.5Ba0.5MnO3 powder by microwave-hydrothermal (MH) accelerated solid state reaction (SSR) route is reported. In this method, SSR is accelerated by use of MH route. MH route decreases the formation temperature to 900 °C and reaction time to 8 h when compared to 1400 °C and 48 h, respectively, for conventional solid state reaction method. The materials are characterized by powder XRD, SEM, TEM, temperature dependence of AC susceptibility and four-probe magnetoresistance technique in a magnetic field of 1 T. XRD data show the formation of the desired phase without any secondary phases. SEM studies reveal agglomeration nature of primary particles with agglomerate size ∼1 μm and the TEM picture supports SEM analysis. AC susceptibility, resistivity in the absence of magnetic field (ρ0) and in the presence of the field (ρH) and magnetoresistance: MR=[(ρ0−ρH)/ρ0] all show a peak or a small structure at ∼200 K indicative of a magnetic phase transition at this temperature.
... October 1990 Low-temperature synthesis ofultrafine barium titanate (BaTi03) using organometal... more ... October 1990 Low-temperature synthesis ofultrafine barium titanate (BaTi03) using organometallic barium and titanium precursors ^ HS Potdar, P. Singh, SB Deshpande ... highly exothermic reaction with a peak at 330 C to 3 70 C resulting from oxidation of carbon mon-Dxide to ...
A systematic evaluation of the gas sensing properties of Cu-modified BaTiO3 pellets for CO, H2 an... more A systematic evaluation of the gas sensing properties of Cu-modified BaTiO3 pellets for CO, H2 and LPG gases was carried out in the present investigation. The concentration of Cu in BaTiO3 was varied systematically from 1 to 11 wt.%. The highest value of sensitivity factor (SF) of 1388 for H2 and 557 for CO gases was obtained at considerably lower optimum operating temperatures of 180 and 250 °C respectively for 9 wt.% of Cu concentration. The sensor tends to saturate at 5.0 and 3.5% for H2 and CO gases respectively. The XRD and SEM characterization techniques were employed to understand the possible reasons for the high performance of the sensor material with 9 wt.% of Cu. The study revealed that this sensor material shows extraordinarily promising properties for H2 gas sensing application.
The controlled hydrolysis reaction of titanium tetrabutoxide in presence of acetic acid in isopro... more The controlled hydrolysis reaction of titanium tetrabutoxide in presence of acetic acid in isopropanol, i.e. in non-aqueous media was adopted in the present work for the synthesis of nanocrystalline titania followed by aging at ambient conditions for longer duration. The powder XRD shows that the as-dried precursor (without any aging) is non-crystalline in nature. However, room temperature aging for longer
A simple chemical route is developed to generate maghemite (γ-Fe2O3) nano-particles, dispersed in... more A simple chemical route is developed to generate maghemite (γ-Fe2O3) nano-particles, dispersed in organic solvents via a thermal decomposition of an ironhydroxy oleate precursor. An ironhydroxy oleate precursor was generated by chemical reaction of mixed ...
... Publishing Company SOLAR SELECTIVE COPPER-BLACK LAYERS BY AN ANODIC OXW TTON PROCESS* HS POTD... more ... Publishing Company SOLAR SELECTIVE COPPER-BLACK LAYERS BY AN ANODIC OXW TTON PROCESS* HS POTDAR, Neela PAVASKAR, Anjana MITRA and APB SINHA Nationai ... asa/e (Kl 300 0.95 0.2 4.75 373 0.95 0.34 2.794 100 9-07mA /cm2 80 9~67mA /cm2 w U zc ...
ABSTRACT Ferroelectric BiFeO(3) (BFO) nanoparticles deposited on epitaxial substrates of SrRuO(3)... more ABSTRACT Ferroelectric BiFeO(3) (BFO) nanoparticles deposited on epitaxial substrates of SrRuO(3) (SRO) and La(1-x)Sr(x)MnO(3) (LSMO) were studied using band excitation piezoresponse spectroscopy (BEPS), piezoresponse force microscopy (PFM), and ferromagnetic resonance (FMR). BEPS confirms that the nanoparticles are ferroelectric in nature. Switching behavior of nanoparticle clusters were studied and showed evidence for inhomogeneous switching. The dimensionality of domains within nanoparticles was found to be fractal in nature, with a dimensionality constant of similar to 1.4, on par with ferroelectric BFO thin-films under 100 nm in thickness. Ferromagnetic resonance studies indicate BFO nanoparticles only weakly affect the magnetic response of LSMO. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3671392]
A simple one-step cation-exchange reaction between the stoichiometric solutions of ammonium titan... more A simple one-step cation-exchange reaction between the stoichiometric solutions of ammonium titanyl oxalate (ATO) and barium hydroxide+ strontium nitrate at room temperature (RT) is investigated successfully for the quantitative precipitation of barium ...
A simple citrate gel route was adopted for the preparation of bismuth titanate (Bi4Ti3O12) powder... more A simple citrate gel route was adopted for the preparation of bismuth titanate (Bi4Ti3O12) powders. Stoichiometric quantities of BiCl3 and TiOCl2 were mixed with required amount of citric acid, and the mixture was heated on a water bath. This leads to formation of gel, which was decomposed at 673K. Formation of bismuth titanate was observed on calcining powders at 973K
ABSTRACT Submicron-sized, spherical, stoichiometric strontium substituted barium titanate: Ba0.75... more ABSTRACT Submicron-sized, spherical, stoichiometric strontium substituted barium titanate: Ba0.75Sr0.25TiO3 (BST) powders are prepared by microwave-hydrothermal (MH) route under the MH conditions of 200 °C, 200 psi, and 30 min in strongly alkaline conditions (pH>12) using potassium titanyl oxalate (KTO) and nitrates of Ba and Sr as the starting precursors and KOH as the mineralizer. The characterization studies by XRD, XRF and SEM indicated that stoichiometric cubic BST powders (a0=3.992 Å) were obtained by adjusting MH conditions mentioned earlier and keeping the (Ba+Sr)/Ti ratio in starting solution slightly in excess (∼1.06).
ABSTRACT Synthesis of La0.5Ba0.5MnO3 powder by microwave-hydrothermal (MH) accelerated solid stat... more ABSTRACT Synthesis of La0.5Ba0.5MnO3 powder by microwave-hydrothermal (MH) accelerated solid state reaction (SSR) route is reported. In this method, SSR is accelerated by use of MH route. MH route decreases the formation temperature to 900 °C and reaction time to 8 h when compared to 1400 °C and 48 h, respectively, for conventional solid state reaction method. The materials are characterized by powder XRD, SEM, TEM, temperature dependence of AC susceptibility and four-probe magnetoresistance technique in a magnetic field of 1 T. XRD data show the formation of the desired phase without any secondary phases. SEM studies reveal agglomeration nature of primary particles with agglomerate size ∼1 μm and the TEM picture supports SEM analysis. AC susceptibility, resistivity in the absence of magnetic field (ρ0) and in the presence of the field (ρH) and magnetoresistance: MR=[(ρ0−ρH)/ρ0] all show a peak or a small structure at ∼200 K indicative of a magnetic phase transition at this temperature.
... October 1990 Low-temperature synthesis ofultrafine barium titanate (BaTi03) using organometal... more ... October 1990 Low-temperature synthesis ofultrafine barium titanate (BaTi03) using organometallic barium and titanium precursors ^ HS Potdar, P. Singh, SB Deshpande ... highly exothermic reaction with a peak at 330 C to 3 70 C resulting from oxidation of carbon mon-Dxide to ...
A systematic evaluation of the gas sensing properties of Cu-modified BaTiO3 pellets for CO, H2 an... more A systematic evaluation of the gas sensing properties of Cu-modified BaTiO3 pellets for CO, H2 and LPG gases was carried out in the present investigation. The concentration of Cu in BaTiO3 was varied systematically from 1 to 11 wt.%. The highest value of sensitivity factor (SF) of 1388 for H2 and 557 for CO gases was obtained at considerably lower optimum operating temperatures of 180 and 250 °C respectively for 9 wt.% of Cu concentration. The sensor tends to saturate at 5.0 and 3.5% for H2 and CO gases respectively. The XRD and SEM characterization techniques were employed to understand the possible reasons for the high performance of the sensor material with 9 wt.% of Cu. The study revealed that this sensor material shows extraordinarily promising properties for H2 gas sensing application.
The controlled hydrolysis reaction of titanium tetrabutoxide in presence of acetic acid in isopro... more The controlled hydrolysis reaction of titanium tetrabutoxide in presence of acetic acid in isopropanol, i.e. in non-aqueous media was adopted in the present work for the synthesis of nanocrystalline titania followed by aging at ambient conditions for longer duration. The powder XRD shows that the as-dried precursor (without any aging) is non-crystalline in nature. However, room temperature aging for longer
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