Engineering

Publication Search Results

Now showing 1 - 10 of 77
  • (1999) Bandyopadhyay, Srikanta; Gowripalan, Nadarajah; Rizkalla, S; Dutta, P; Bhattacharyya, D
    Conference Paper

  • (2000) Kaog, G J P; Gowripalan, Nadarajah; Bandyopadhyay, Srikanta
    Conference Paper

  • (2000) Bandyopadhyay, Srikanta; Sowmya, Arcot; Maulik, Ujjwal
    Conference Paper

  • (2000) Teoh, C; Sowmya, Arcot; Bandyopadhyay, Srikanta
    Conference Paper

  • (2000) Bandyopadhyay, Srikanta; Gowripalan, Nadarajah; Drayton, Noel; Heslehurst, Rikard
    Conference Paper

  • (2002) Bandyopadhyay, Srikanta; Gowripalan, Nadarajah; Rizkalla, S
    Book

  • (1995) Mubaraki, Brian; Bandyopadhyay, Srikanta; Fowle, R; Mathew, Philip; Heath, P
    Journal Article

  • (1995) Zhao, Yong; Chen, B; Sorrell, Charles; He, Ying; Zuge, X; Chen, Zhixin
    Journal Article
    The scaling behaviour of vortex-glass superconductivity is studied, by measuring the resistive transition as well as the I-V curve under a variety of magnetic fields, in a series of V doped YBa2Cu307_y samples with different grain sizes. The equilibrium phase boundary line between the normal and superconducting phases in the H-T plane obtained by fitting the resistive transition is consistent with that obtained by the I-V curve measurements. As the magnetic field is lower than a certain value, Hs, the scaling exponents are magnetic-field independent, but at H = H s, they begin to increase with the magnetic field and gradually get saturation. The switch field, Hs, decreases with decreasing the grain size in the samples. The results show that the magnetic-field-dependent scaling behaviour of the I-V curve observed in weak-link containing systems originates from the transition of a "weak" vortex-glass state to a "strong" vortex-glass state.

  • (1995) Han, Shaowei; Gu, Genda; Zhao, Yong; Russell, Graeme; Koshizuka, N
    Journal Article
    Two types of Bi-2212 single crystals, one type having a low T c and the other having a high T¢ were annealed in air at different temperatures over the range 450°C to 750°C followed by furnace cooling. The transition temperature of the crystals with low T c (~ 56 K) increased with increase of annealing temperature, while the crystals with high Tc (~ 91 K) had just the opposite behaviour under the same annealing conditions. It is indicated that the quality of as-grown crystal has a significant effect on the superconducting properties of the annealed crystal. The c-axis values for both types of crystals decreased with increase of annealing temperature. According to the relationship between c-axis values and the oxygen content, our results confirmed the existence of a dome-shaped curve of T¢ with carrier concentration in Bi-2212 single crystal similar to that in Bi-2212 compound reported previously by Groen and de Leeuw [Physica C 159 (1989) 417]. By studying the increase of annealing time at a fixed temperature of 650°C, T¢ and ATe were found to change very little for both types of crystals. Thus, T c and AT~ were more sensitive to annealing temperature than to annealing time. XRD, SEM and EDS revealed that a small quantity of powder phase appeared after annealing at temperatures above 500°C for both types of crystals. This powder phase had the Bi-2212 composition, which indicated that the integrity of the Bi-2212 single crystals was significantly degraded by the annealing process.

  • (1998) Gu, Genda; Han, Shaowei; Lin, Zheng; Zhao, Yong; Russell, Graeme
    Journal Article