Showing papers in "Materials Letters in 1991"

TL;DR: In this article, a combustion synthesis method was developed to simply and rapidly prepare YBa2Cu3O7−x and YBa 2cu3O−x/Ag from an aqueous solution of the metal nitrates and glycine.

TL;DR: LiNbO3 thin films were prepared on sapphire substrates by a sol-gel process using lithium ethoxide and niobium pentaethoxide as discussed by the authors, which showed a higher preferred orientation in the same crystal plane as the orientation of the substrate.

TL;DR: In this article, the chemical reactions between polyacrylic acid (PAA) and various divalent metal oxides (MO; M = Ca, Mg, Cu, Zn) were studied by Fourier transform infrared spectroscopy (FTIR).

TL;DR: In this paper, the full powder diffraction pattern of hexagonal Fe 17 Nd 5, a = 2.0214 nm, c = 1.2329 nm, has been verified that the phase has been observed under different experimental conditions.

TL;DR: In this article, a large elongation of 600% was obtained at an initial strain rate of 2 × 10 −1 s −1 1 s−1, and their properties were investigated at an elevated temperature of 818 K.

TL;DR: In this article, thin films containing liquid crystal droplets have been prepared by trapping of a solution of commercial mixture Phase 5 in a polymerizing ethyl-triethoxysilane.

TL;DR: In this article, the acidity of the catalysts has been determined by the amine titration method and the catalytic activity of these catalysts towards the conversion of ethanol and isopropanol was determined at different temperatures.

TL;DR: In this paper, a mixture of methanol and chloroform was found to be a suitable solvent for crystal growth and crystals up to the size of 7 × 5 × 4 mm3 were grown for optical characterization.

TL;DR: In this paper, a warm-rolled binary Mg-8.5 wt.% Li alloy exhibits superplasticity at intermediate temperatures, and the increase in the value of the strain-rate-sensitivity exponent and the change in the microstructure suggest that the Mg 8.5wt.

TL;DR: In this article, thin films of TiC have been grown on Si (100) substrates by pulsed laser evaporation and analysis by X-ray photoelectron spectroscopy and by Auger sputter depth profiles indicates that the films grown between RT and 500° C are stoichiometric TiC.

TL;DR: In this paper, the effect of preparation procedure of mixed transition-metal oxides on their catalytic properties has been investigated and it was found that catalytic activity depends on their preparation procedure.

TL;DR: In this paper, a carbon sheath is formed on the fiber surface under most, but not all, process conditions, which significantly improves the hydrolytic stability of the resulting fibers.

TL;DR: Amorphous ribbons were prepared by the conventional single-roller technique and after annealing at 545°C and 550°C for 1 h in N 2 and H 2 atmospheres, respectively, they became nanocrystalline with 12 nm grains of the Fe-Si phase.

TL;DR: In this paper, p-AgGaSe 2 /n-CdS heterojunctions were fabricated and the J - V, C - V and spectral response characteristics were studied and typical cell parameters obtained were: V oc =510 mV, J sc = 13.8 mA/cm 2, FF=0.55 and gh =4.5%.

TL;DR: The formation of binary Sm5Fe17 was reported for the first time in this article, and the room-temperature i H c observed was 7 kOe. It was also shown that V and Ti replacements for approximately 10% of the Fe yield a systematic and expected expansion of the unitcell volume.

TL;DR: In this article, the extent of grain orientation on sintering is quantified in terms of the Lotgering orientation factor from the XRD intensities of pellets sintered at different temperatures.

TL;DR: In this paper, single-crystal fibers of the layered perovskite A 2 B 2 O 7 (A=La, Nd, Ca, B=Ti, Nb) were grown by the laser-heated pedestal growth technique.

TL;DR: In this article, semiconducting cuprous oxide films were prepared by electrodeposition onto copper substrates from an alkaline CuSO4 bath at temperatures between 40 and 60°C.

TL;DR: The stabilities of Si(OCH 3 ) 4 and Si(OC 2 H 5 ) 4 have been studied pyrolytically using highly diluted mixtures near atmospheric-pressure conditions as mentioned in this paper.

TL;DR: In this paper, infrared reflectance spectra were measured for sodium calcium silicate glass which had undergone ion exchange/heat treatment, and were interpreted on the basis of structural changes in the near surface region of the glass.

TL;DR: Based on microscopic, X-ray diffraction and magnetic analyses of Co-rich CoZr and Co-Zr-B alloys, combined with available literature information, the source of magnetic hardness is traced to two phases, pseudohexagonal CoxZr (x ≈ 5), and boron-stabilized hexagonal Co5−xZrBx which has a structure that is derived from the CaCu5 type by Boron replacing Co.

TL;DR: In this article, gallium nitride (GaN) films were grown by reactive rf magnetron sputtering on sapphire substrates at substrate temperatures between 640 and 680°C. Nitrogen incorporation and crystal quality of GaN films were examined as a function of substrate temperature and nitrogen partial pressure.

TL;DR: A superconductor oxide composite is prepared using a press coating technique as mentioned in this paper, and the coated layers on various substrates exhibit good adhesion, textured microstructure, and improved Jc

TL;DR: In this article, the Nishiyama-Wassermann relationship between the 12 orientation variants and the 24 habit-plane variants was determined, and the total variant selection is a combination of both selection rules.

TL;DR: In this article, a modification of the oxalate coprecipitation process for preparing high-Tc superconducting oxides is reported, which can be employed for large quantity preparation of the YBa2Cu3Oy system.

TL;DR: The Avrami and Kissinger theories for the study of the crystallization kinetics of amorphous metallic alloys are briefly reviewed in this article, and it is shown that due to the mathematical expressions of the non-isothermal equations for both theories, and the relative order of magnitude of the commonly observed crystallization temperatures and heating rates used in DSC equipment, both theories give very similar results.

TL;DR: In this paper, the effects of chelation on the crystallization and microstructures of SrTiO3 sol-gel films on fused silica substrates were studied and the results indicated segregation of small crystallites for thin films obtained from triethanolamine and acetylacetone chelated precursor solutions.

TL;DR: In this paper, perovskite CaMnO3 and its oxygen-deficient derivatives have been prepared from solid solution precursor with a calcite-type structure using MnO6 octahedra and MnO5 square pyramids.

TL;DR: In this paper, the preparation of nanosize prismatic SnO 2 particles of fairly narrow size distribution by forced hydrolysis at 100°C of acidic SnCl 4 solutions is described.