Showing papers by "Pushan Ayyub published in 1987"
TL;DR: In this article, the structural and dielectric properties of Ferroelectric SbNbO4, antiferroelectric BiBiO4 and their solid solutions have been synthesized in the ceramic form through high temperature solid state reactions.
Abstract: Ferroelectric SbNbO4, antiferroelectric BiNbO4 and their solid solutions have been synthesized in the ceramic form through high temperature solid state reactions. X-ray diffraction and dielectric measurements have been carried out to investigate the structural and dielectric properties of this system as a function of both temperature and concentration. These studies indicate the presence of at least two concentration-dependent structural phase transitions. This is also corroborated by Raman scattering measurements on the entire system. Soft modes and other vibrational properties of the solid solution are discussed.
9 citations
TL;DR: In this article, four-probe DC measurements in a sample of X-ray single phase ErBa2Cu3O7-x have revealed a large drop in the resistivity to near-zero values at a temperature as high as 260 K.
Abstract: Four-probe DC measurements in a sample of X-ray single phase ErBa2Cu3O7-x have revealed a large drop in the resistivity to near-zero values at a temperature as high as 260 K. The high-temperature anomaly disappeared on the third thermal cycle and the sample superconducted at the 'normal' critical temperature of 90 K. This indicates that the high-temperature resistive anomaly probably originates from a granular minority phase.
3 citations
TL;DR: In this paper, superconductivity has been observed in a Tm-Ba-Cu-O system with Tc=89 K. Magnetisation measurements indicated that at least 8% of the sample was superconducting.
Abstract: Superconductivity has been observed in a Tm-Ba-Cu-O system with Tc=89 K. Even though the predominant phase on this system was found to be TmBa2Cu3O9-x, this compound could not be synthesised as a single phase. Magnetisation measurements indicated that at least 8% of the sample was superconducting. At 10 K, the lower critical field was found to be 1.5 kG.
2 citations
TL;DR: In the pseudo-binary alloy system U(Fe1−x Cox)2, the ordering transition temperature and the magnetic moment decrease rapidly with x as discussed by the authors. But the observed hyperfine field at the57Fe nucleus is much reduced with respect to that in UFe2.
Abstract: In the pseudo-binary alloy system U(Fe1−x Cox)2, the ordering transition temperature and the magnetic moment decrease rapidly with x.57Fe Mossbauer measurements on the alloys (x=0.08 and 0.20) have been performed as a function of temperature. The observed hyperfine field at the57Fe nucleus is much reduced with respect to that in UFe2.