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Neutron Diffraction by the Flux Line Lattice in YBa 2 Cu 3 O 7−δ Single Crystals
Author(s) -
Brandstätter G.,
Weber H. W.,
Chattopadhyay T.,
Cubitt R.,
Fischer H.,
Wylie M.,
Emel'chenko G. A.,
Wiedenmann A.
Publication year - 1997
Publication title -
journal of applied crystallography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.429
H-Index - 162
ISSN - 1600-5767
DOI - 10.1107/s0021889897001854
Subject(s) - pairing , superconductivity , condensed matter physics , neutron diffraction , diffraction , scattering , lattice (music) , neutron scattering , single crystal , penetration depth , physics , high temperature superconductivity , optics , nuclear magnetic resonance , acoustics
Small‐angle neutron diffraction was used to image the mixed state in a large superconducting YBa 2 Cu 3 O 7−δ single crystal. The flux line lattice was observed in fields up to 2 T at various temperatures from 2.4 to 80 K. The integrated intensity I of the (10) reflection was calculated as a function of temperature for three different fields (0.8, 1 and 2 T). From these I ( T ) curves, the magnetic penetration depth λ ( T ) was obtained on an absolute scale. This quantity is of particular interest, since it provides information on the nature of the pairing mechanism in the superconductor, i.e . the symmetry of the wavefunction of the electron pairs. The results are discussed in terms of BCS theory ( s ‐wave pairing) and of d ‐wave pairing with and without impurity scattering.