Studies of longitudinal and transverse resistivities of YBa2Cu3Oy/R0.7M0.3MnO 3 superlattices, in which R = La or Nd and M = Ca or Sr
Journal
Superconductor Science and Technology
Journal Volume
15
Journal Issue
7
Pages
1011-1016
Date Issued
2002
Author(s)
Abstract
We measured the longitudinal and transverse Hall resistivities of YBa2Cu3Oy/R1-xMxMnO3 superlattices in magnetic fields to study the transport properties, in which R = La or Nd and M = Ca or Sr. The resistive transition in the magnetic field shows a thermally activated flux flow behaviour. The flux pinning ability of the superlattice is reduced when the coupling strength between YBa2Cu3Oy layers is decreased. The transverse Hall resistivity shows sign reversal for samples with strong pinning ability. The sign reversal diminishes as the pinning force is reduced. The magnetoresistance (MR) ratio, |Δρ(H) - Δρ(H = 0)|/Δρ(H), of the YBa2Cu3Oy/R1-xMxMnO3 superlattice is affected by the coupling strength of R1-xMxMnO3 layers. The peak values of the MR ratio were shifted to lower temperatures in superlattices due to the lowering of the magnetic ordering in ferromagnetic layers.
Type
journal article