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Phase separation and superconductivity in La{sub 2}CuO{sub 4+{delta}}: Effects of oxygen diffusion

Conference ·
OSTI ID:10165797
; ; ; ; ;  [1];  [2]
  1. Los Alamos National Lab., NM (United States)
  2. Sandia National Labs., Albuquerque, NM (United States)
In oxygen-annealed La{sub 2}CuO{sub 4+{delta}} ({delta}{approximately}0.03), bulk magnetization measurements show an increase of {approximately}4K in the superconducting T{sub c} when the sample is cooled slowly through a narrow temperature range near 195K. At this temperature, {sup 139}La NQR spectra exhibit a concomitant appearance of an anomalous feature associated with the metallic phase whose spectral weight increases with cooling rate. The data suggests a distribution of local structures and annealing-dependent volume fraction on this part of the sample. Interpretation of these results in terms of oxygen diffusion in a phase separated material is considered and a picture consistent with the observed changes in T{sub c} is obtained. Other possible origins of these anomalies and the role they play in determining the superconducting properties of this system are discussed.
Research Organization:
Los Alamos National Lab., NM (United States)
Sponsoring Organization:
USDOE, Washington, DC (United States)
DOE Contract Number:
W-7405-ENG-36
OSTI ID:
10165797
Report Number(s):
LA-UR--93-2162; CONF-930367--7; ON: DE93016610
Country of Publication:
United States
Language:
English