TY - JOUR
T1 - Structural characterization of La2-xMxCuO4 (M = Sr,Ba) samples by synchrotron x-ray and neutron powder diffraction techniques
AU - Cox, D. E.
AU - Moss, S. C.
AU - Chu, C. W.
N1 - Funding Information:
The work at Brookhaven was supported by the Division of Materials Sciences, U.S. Department of Energy, under Contract No. DE-ACO2-76CH00016 (DEC). The work at Houston was supported by the National Science Foundation, Grant No. DMR-8603662 (SCM), and DMR-8616539 and the Texas Center for Superconductivity (RLM, PHH, and CWC).
PY - 1988/12
Y1 - 1988/12
N2 - High-resolution synchrotron x-ray powder diffraction studies on samples of La2-xMx Cu04 (M = Sr,Ba) prepared by standard ceramic techniques show that macroscopic compositional inhomogeneities may exist that are unlikely to be revealed by conventional x-ray diffraction methods. Rietveld refinement of neutron data collected at 200, 50, and 11 K from one such sample, nominally La1.8 Sr0.2 Cu04, gave satisfactory fits to a tetragonal structure of K2NiF4 type at all three temperatures. However, careful individual peak fits revealed that part of the sample transforms to orthorhombic between 200 and 50 K. It is suggested that this multiphase character has an important influence on the superconducting properties.
AB - High-resolution synchrotron x-ray powder diffraction studies on samples of La2-xMx Cu04 (M = Sr,Ba) prepared by standard ceramic techniques show that macroscopic compositional inhomogeneities may exist that are unlikely to be revealed by conventional x-ray diffraction methods. Rietveld refinement of neutron data collected at 200, 50, and 11 K from one such sample, nominally La1.8 Sr0.2 Cu04, gave satisfactory fits to a tetragonal structure of K2NiF4 type at all three temperatures. However, careful individual peak fits revealed that part of the sample transforms to orthorhombic between 200 and 50 K. It is suggested that this multiphase character has an important influence on the superconducting properties.
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U2 - 10.1557/JMR.1988.1327
DO - 10.1557/JMR.1988.1327
M3 - Article
AN - SCOPUS:0024105709
SN - 0884-2914
VL - 3
SP - 1327
EP - 1335
JO - Journal of Materials Research
JF - Journal of Materials Research
IS - 6
ER -