Pyrolysis Of Organic Acid Salts Research Articles

Structural and electrical properties of Sb-doped SnO2 thin films prepared by metal organic decomposition

Sb-doped SnO2 thin films were prepared by metal organic decomposition through pyrolysis of organic acid salts. The dependence of the structural and electrical properties of the films on the Sb concentration, annealing temperature, and film thickness was investigated. A polycrystalline rutile structure was confirmed for all samples using X-ray diffraction and atomic force microscopy measurements. Structural properties of the samples improved with an increase of the annealing temperature, and deteriorated with an increase of the Sb concentration. The resistivity of the Sb-doped SnO2 thin films decreased above 3.0 at.% Sb doping. It was suggested that for each film thickness, there was an optimum annealing temperature in terms of the resistivity. The lowest resistivity (3.6 × 10−3 Ωcm) was obtained for the sample with a Sb concentration of 3.0 at.% and a film thickness of 550 nm, that was annealed at 900 °C.

Effects of annealing temperature and Eu concentration on the structural and photoluminescence properties of Eu-doped SnO2 thin films prepared by a metal organic decomposition method

In this study, Eu-doped SnO2 thin films were prepared by a metal organic decomposition method through a pyrolysis of organic acid salts. The effects of annealing temperature and Eu concentration on the structural and photoluminescence properties of the films were investigated. X-ray diffraction measurements showed that the crystal structure corresponded to tetragonal rutile SnO2 regardless of the annealing temperature or Eu concentration. Additionally, X-ray diffraction, Fourier transform infrared spectroscopy and atomic force microscopy measurements indicated an improvement in crystalline quality with increasing annealing temperature. Photoluminescence spectra exhibited Eu-related emissions around 588–599 nm and 620 nm. It was found that the photoluminescence properties were strongly dependent on both the annealing temperature and Eu concentration. The highest photoluminescence intensity around 588–599 nm was obtained for an Eu concentration of 7.2 at.% for samples annealed at 1000 °C.

Preparation of Bi [sbnd]Sr [sbnd]Ca [sbnd]Cu [sbnd]O superconducting tape by pyrolysis of organic acid salts

We applied a partial melting technique to 2212 tape prepared by pyrolysis of organic acid salts. The thermal analysis of the tape in the heating and cooling process indicated that the partial melting began at 870°C and the complete solidification occurred at 840°C. High-temperature X-ray diffraction measurement during the cooling process indicated that the 2212 phase grew rapidly in a vicinity of 850°C, and the 2201 phase was more stable at low temperature than the 2212 phase. J c of the tape depended on the cooling rate, and was 1.5 × 10 5 A/cm 2 in 2 T and 4.2 K when it was prepared with a cooling rate of 0.2°C/min.

Bi-Pb-Sr-Ca-Cu-O High-Tc Superconducting Fibers Prepared by the Pyrolysis of Organic Acid Salts

Bi-Pb-Sr-Ca-Cu-O high-Tc superconducting solid fibers were successfully prepared from the viscous mixture of organic acid salts containing oxide powders followed by the pyrolysis of organic acid salts. The addition of Pb efficiently enhanced the formation of the (Bi, Pb):Sr:Ca:Cu=2:2:2:3 phase. The Tc(end) of fibers was constantly over 100 K, the maximum Tc(end) being 108 K. The tensile strength of fibers with a Tc(end) of 108 K was 18 MPa.

Preparation of Y-Ba-Cu-O superconducting tape by pyrolysis of organic acid salts

A Y-Ba-Cu-O superconducting tape of 124 phase was successfully synthesized at atmospheric pressure by pyrolysis of organic acid salts. T/sub c(on)/=80 K and T/sub c(end)/=70 K were obtained along with a J/sub c/ of 2*10/sup 4/ A/cm/sup 2/ at 4.2 K and 0 T. An addition of calcium was found to elevate the T/sub c/ and improve the compactness of the film. The J/sub c/ of this sample is 3.2*10/sup 4/ A/cm/sup 2/ at 4.2 K and 0 T. The J/sub c/-B characteristic is better than that of the 124 phase without substitution.

Preparation of Y‐Ba‐Cu‐O tapes by pyrolysis of organic acid salts

AbstractHigh‐TC superconducting Y‐Ba‐Cu‐O films were prepared on certain ceramic and metal substrates by pyrolysis of 2‐ethylhexanoates. Only the films on MgO, yttria‐stabilized zirconia (YSZ), and Ag substrates exhibited the superconducting transition above liquid nitrogen temperature. Transition temperatures (TC) of 82, 85, and 82 K were observed in films of MgO, YSZ, and Ag substrates. The important factors in preparing superconducting films on substrates are the reactivity of the films and the substrates and the difference in their thermal expansions. The Y‐Ba‐Cu‐O films were well suited for use with MgO, YSZ, and Ag substrates. Long superconducting tapes were produced on Ag substrate; flexible tape with a critical current density JC of 3 · 103 A/cm2 at 77 K has now been prepared.

有機酸塩熱分解法による１２４相Ｙ‐Ｂａ‐Ｃｕ‐Ｏ超伝導長尺テープの作製

It is known that the 124 phase Y-Ba-Cu-O superconductor is stabler on heating rather than that 123 phase. Many studies reported that 124 phase was formed in high pressure oxigen atomosphere. In order to form the phase at ordinary pressure, the alkali carbonate has been used as catalysts. So it has been difficult to prepare the long tape.We succeeded in preparing the 124 phase Y-Ba-Cu-O superconducting thick film on Ag tape by pyrolysis of organic acid salts at ordinary pressure. The length of the tape was about 6m. The superconducting tape had 80K of Tc onset, 70K of Tc endpoint, and 2×104A/cm2 of Jc at 4.2K.We confirmed the increases of Tc of Ca-substituted sample in the same process.

有機酸塩熱分解法による１２３相Ｙ‐Ｂａ‐Ｃｕ‐Ｏ超伝導長尺テープの作製

For the purpose of the application of superconducting oxides, preparation of the long wire and tape with low dispersion of Jc is very important. We have been attempted to preparate the long superconducting oxide tape by pyrolysis of organic acid salts on metal tapes.In this paper we describe a study of the preparation of c-axis orientated 123 phase Y-Ba-Cu-O superconducting thick film on Ag tape with about 10m length. This tape had 1.5×104A/cm2 and 9×104A/cm2 of critical current densities (Jc) at 77k OT and 4.2K OT, respectively. The dispersion of Jc value was very little.

Preparation of Superconducting Bi-Sr-Ca-Cu-O Films on Metal Substrates Using ZrO<sub>2</sub> as a Buffer Layer by Pyrolysis of Organic Acid Salts

High-Tc superconducting Bi-Sr-Ca-Cu-O films were prepared on some metal substrates by pyrolysis of 2-ethylhexanoates, with or without ZrO2 as a buffer layer. With respect to superconducting transition temperature (Tc), the films prepared on ZrO2/Ag substrates have the highest of all the present films, those were Tc (onset)=90K and Tc (end)=80K. Without the buffer layer, only the films on Ag, stainless steel and hastelloy substrates showed the superconducting transition, and with the layer of ZrO2, Tc (end) distinctly increased for them and, moreover, some films on other metals such as Cu have Tc (onset) above 10K. The ZrO2 buffer layer seems to be appropriate to form homogeneous films on metal substrates.