vijaykumar chaudhari | RTM Nagpur University (original) (raw)

vijaykumar  chaudhari

A enthusiastic researcher and courageous learner
Phone: +919021691529
Address: Department of Physics, RTM Nagpur University, Nagpur-440033 (MS) India

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Papers by vijaykumar chaudhari

Research paper thumbnail of Sr-doped Sm2CuO4 cathode for intermediate temperature solid oxide fuel cells

Solid State Ionics, 2014

Abstract The Sm 2 - x Sr x CuO 4 - d is single-phase with a tetragonal structure across composit... more Abstract The Sm 2 - x Sr x CuO 4 - d is single-phase with a tetragonal structure across compositional range 0 x 2.8 Sr 0.2 CuO 4 - d exhibits maximum dc conductivity (6.8(2) S cm − 1 at 640 °C) and minimum activation energy ( E a = 0.400(6) eV) among studied solid solutions. Minimum polarization resistance ( R p ) value of 1.57(3) Ω cm 2 is obtained at 700 °C for Sm 2.8 Sr 0.2 CuO 4 - d . Low-frequency impedance spectra are modeled using Gerischer element. Magnitude of Gerischer impedance decreases significantly with increase in Sr content. Oxygen partial pressure-dependent polarization study suggests that non-charge transfer oxygen-adsorption desorption and diffusion are important steps during overall oxygen reduction reaction processes.

Research paper thumbnail of Synthesis and characterization of Ce-doped Sm2CuO4 + δ cathode for IT-SOFC applications

Ionics

Single-phase solid solutions of Sm 2 − x Ce x CuO 4 + δ (0.05 ≤ x ≤ 0.20) with tetragonal structu... more Single-phase solid solutions of Sm 2 − x Ce x CuO 4 + δ (0.05 ≤ x ≤ 0.20) with tetragonal structure are synthesized using acetate combustion followed by sintering at 1373 K for 10 h. X-ray powder diffraction and transmission electron microscopy studies confirmed the formation of solid solution in a single phase. Maximum conductivity (σ = 96.0 ± 0.5 S cm −1 at 973 K) giving composition Sm 1.90 Ce 0.10 CuO 4 offers the minimum activation energy (E a = 0.32 ± 0.004 eV) among all prepared composi-t i on s. L o w e s t c at h od e p o l a r i za t i on re s i s t an c e (R p = 3.92 ± 0.07 Ω cm 2 at 973 K) and activation energy (E a = 1.12 ± 0.03 eV) values across the measured temperature range are obtained for Sm 1.90 Ce 0.10 CuO 4. The impedance data fitted well to the Gerischer model indicates that a chemical-electrochemical-chemical-type reaction occurred at the mixed electronic-ionic conducting cathode.

Research paper thumbnail of An investigation on strontium doped Sm 2 NiO 4þd cathode for intermediate temperature solid oxide fuel cells

Research paper thumbnail of Sr-doped Sm2CuO4 cathode for intermediate temperature solid oxide fuel cells

The Sm2 - xSrxCuO4 - d is single-phase with a tetragonal structure across compositional range 0-0... more The Sm2 - xSrxCuO4 - d is single-phase with a tetragonal structure across compositional range 0-0.5. Sm1.8Sr0.2CuO4 - d exhibits maximumdc conductivity (6.8(2) S cm−1 at 640 °C) and minimum activation energy (Ea = 0.400(6) eV) among studied solid solutions. Minimum polarization resistance (Rp) value of 1.57(3) Ω cm2 is obtained at 700 °C for Sm1.8Sr0.2CuO4 - d . Low-frequency impedance spectra are modeled using Gerischer element. Magnitude of Gerischer impedance decreases significantly with increase in Sr content. Oxygen partial pressure-dependent polarization study suggests that non-charge transfer oxygen-adsorption desorption and diffusion are important steps during overall oxygen reduction reaction processes

Research paper thumbnail of An investigation on strontium doped Sm2NiO4+d cathode for intermediate temperature solid oxide fuel cells

The Sm2-xSrxNiO4+d when x = 0.4-1.0 solid solutions are synthesized by combustion followed by si... more The Sm2-xSrxNiO4+d when x = 0.4-1.0 solid solutions are synthesized by combustion followed by sintering at 1100 C for 10 h, yield crystallite size in the range 73-82 nm. The single phase Sm2xSrxNiO4+d are of orthorhombic and tetragonal crystal structures when x = 0.4-0.7 and x = 0.8-1.0, respectively. The maximum electronic conductivity (s = 0.361 S cm-1 at 640 C) for Sm1.5Sr0.5NiO4+d is due to the extrinsic defects. The decrease in conductivity when x > 0.5 is attributed to the formation of electrically neutral clusters. The narrow particle size distribution with mean particle size 423 nm, of Sm1.5Sr0.5NiO4+d is obtained by ball milling the ink/slurry at 300 revolutions per minute (rpm) for 1 h.
The minimum area specific resistance (ASR) of 2.7 ohm cm2 at 700 C is obtained when x = 0.5, and is attributed to uniform superfine grains and optimum porosity of cathode.

Research paper thumbnail of Sr-doped Sm2CuO4 cathode for intermediate temperature solid oxide fuel cells

Solid State Ionics, 2014

Abstract The Sm 2 - x Sr x CuO 4 - d is single-phase with a tetragonal structure across composit... more Abstract The Sm 2 - x Sr x CuO 4 - d is single-phase with a tetragonal structure across compositional range 0 x 2.8 Sr 0.2 CuO 4 - d exhibits maximum dc conductivity (6.8(2) S cm − 1 at 640 °C) and minimum activation energy ( E a = 0.400(6) eV) among studied solid solutions. Minimum polarization resistance ( R p ) value of 1.57(3) Ω cm 2 is obtained at 700 °C for Sm 2.8 Sr 0.2 CuO 4 - d . Low-frequency impedance spectra are modeled using Gerischer element. Magnitude of Gerischer impedance decreases significantly with increase in Sr content. Oxygen partial pressure-dependent polarization study suggests that non-charge transfer oxygen-adsorption desorption and diffusion are important steps during overall oxygen reduction reaction processes.

Research paper thumbnail of Synthesis and characterization of Ce-doped Sm2CuO4 + δ cathode for IT-SOFC applications

Ionics

Single-phase solid solutions of Sm 2 − x Ce x CuO 4 + δ (0.05 ≤ x ≤ 0.20) with tetragonal structu... more Single-phase solid solutions of Sm 2 − x Ce x CuO 4 + δ (0.05 ≤ x ≤ 0.20) with tetragonal structure are synthesized using acetate combustion followed by sintering at 1373 K for 10 h. X-ray powder diffraction and transmission electron microscopy studies confirmed the formation of solid solution in a single phase. Maximum conductivity (σ = 96.0 ± 0.5 S cm −1 at 973 K) giving composition Sm 1.90 Ce 0.10 CuO 4 offers the minimum activation energy (E a = 0.32 ± 0.004 eV) among all prepared composi-t i on s. L o w e s t c at h od e p o l a r i za t i on re s i s t an c e (R p = 3.92 ± 0.07 Ω cm 2 at 973 K) and activation energy (E a = 1.12 ± 0.03 eV) values across the measured temperature range are obtained for Sm 1.90 Ce 0.10 CuO 4. The impedance data fitted well to the Gerischer model indicates that a chemical-electrochemical-chemical-type reaction occurred at the mixed electronic-ionic conducting cathode.

Research paper thumbnail of An investigation on strontium doped Sm 2 NiO 4þd cathode for intermediate temperature solid oxide fuel cells

Research paper thumbnail of Sr-doped Sm2CuO4 cathode for intermediate temperature solid oxide fuel cells

The Sm2 - xSrxCuO4 - d is single-phase with a tetragonal structure across compositional range 0-0... more The Sm2 - xSrxCuO4 - d is single-phase with a tetragonal structure across compositional range 0-0.5. Sm1.8Sr0.2CuO4 - d exhibits maximumdc conductivity (6.8(2) S cm−1 at 640 °C) and minimum activation energy (Ea = 0.400(6) eV) among studied solid solutions. Minimum polarization resistance (Rp) value of 1.57(3) Ω cm2 is obtained at 700 °C for Sm1.8Sr0.2CuO4 - d . Low-frequency impedance spectra are modeled using Gerischer element. Magnitude of Gerischer impedance decreases significantly with increase in Sr content. Oxygen partial pressure-dependent polarization study suggests that non-charge transfer oxygen-adsorption desorption and diffusion are important steps during overall oxygen reduction reaction processes

Research paper thumbnail of An investigation on strontium doped Sm2NiO4+d cathode for intermediate temperature solid oxide fuel cells

The Sm2-xSrxNiO4+d when x = 0.4-1.0 solid solutions are synthesized by combustion followed by si... more The Sm2-xSrxNiO4+d when x = 0.4-1.0 solid solutions are synthesized by combustion followed by sintering at 1100 C for 10 h, yield crystallite size in the range 73-82 nm. The single phase Sm2xSrxNiO4+d are of orthorhombic and tetragonal crystal structures when x = 0.4-0.7 and x = 0.8-1.0, respectively. The maximum electronic conductivity (s = 0.361 S cm-1 at 640 C) for Sm1.5Sr0.5NiO4+d is due to the extrinsic defects. The decrease in conductivity when x > 0.5 is attributed to the formation of electrically neutral clusters. The narrow particle size distribution with mean particle size 423 nm, of Sm1.5Sr0.5NiO4+d is obtained by ball milling the ink/slurry at 300 revolutions per minute (rpm) for 1 h.
The minimum area specific resistance (ASR) of 2.7 ohm cm2 at 700 C is obtained when x = 0.5, and is attributed to uniform superfine grains and optimum porosity of cathode.

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