Thin whiskers of orthorhombic Bi2Sr2Ca1Cu2Ox have been grown from powders and their resistive transitions have been studied at constant current. The potential difference between the voltage electrodes on some of the whiskers showed an abrupt increase when they were cooled below ∼ 105 K. It is shown that this increase may be explained by one or more intercalated layers of superconducting Bi2Sr2Ca2Cu3Ox inside the bulk Bi2Sr2Ca1Cu2Ox material. The whisker is represented by an orthorhombic solid which extends from -∞ to ∞in the b-direction and has a thickness in the c-direction which is much less than the length in the a-direction. The ratio of the electrical conductivities σaa/σcc is taken to be of the order of 104 as is the case for Bi2Sr2Ca1Cu2Ox. The two-dimensional potential distribution in the whisker satisfies Laplace's equation in a co-ordinate system in which the displacements along the c-direction are scaled by a factor of √(σaa/σcc). This equation is solved by a standard relaxation method. Two cases have been considered. In the first, the entire crystal is in its normal state and in the second there is an intercalated superconducting layer of Bi2Sr2Ca2Cu3Ox perpendicular to the c-direction and inside normally conducting Bi2Sr2Ca1Cu2Ox which constitutes the bulk material. It is this layer which gives rise to the observed anomalous resistive transitions at 105 K and to changes in potential distributions. Figures are presented to illustrate the changes.
- Electrical resistivity
- Intercalated layers
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering