skip to main content

SciTech ConnectSciTech Connect

Title: Hole doping dependence of critical current density in YBa{sub 2}Cu{sub 3}O{sub 7−δ} conductors

One of the central themes in cuprate superconductivity is the evolution of the electronic properties with the charge carrier concentration, p, expressed as the number of holes per Cu ion in the CuO{sub 2} planes. In YBa{sub 2}Cu{sub 3}O{sub 7−δ} (YBCO), p is well known to vary with oxygen content (δ) and with substitution of Ca{sup 2+} for Y{sup 3+}. In this Letter, we show that p also varies with the fraction of Cu–O “chain layer” stacking faults. The resulting parabolic variation in the superconducting transition temperature (T{sub c}) is also well known; however, the effect on the critical current density (J{sub c}) is less well explored. We show that the self-field J{sub c} follows a common trend for all these hole doping methods, rising to a sharp peak on the slightly overdoped side of the T{sub c}(p) parabola. In contrast, the in-field J{sub c} anisotropy at high temperatures and low fields is determined solely by the stacking-fault fraction, not by hole doping, such that a sample free from stacking faults tends towards an isotropic J{sub c}. These results serve to emphasize the role of sample microstructure in determining J{sub c} in-field anisotropy.
Authors:
; ; ;  [1] ; ;  [1] ;  [2]
  1. Robinson Research Institute, Victoria University of Wellington, P.O. Box 33436, Lower Hutt 5046 (New Zealand)
  2. (New Zealand)
Publication Date:
OSTI Identifier:
22299906
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 24; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ANISOTROPY; BARIUM COMPOUNDS; CALCIUM IONS; CHARGE CARRIERS; COPPER COMPOUNDS; CRITICAL CURRENT; CUPRATES; CURRENT DENSITY; HIGH-TC SUPERCONDUCTORS; HOLES; LAYERS; MICROSTRUCTURE; OXYGEN COMPOUNDS; SUPERCONDUCTIVITY; TRANSITION TEMPERATURE; YTTRIUM COMPOUNDS