Polarized-neutron study of the YBa2Cu3O7 system: Granular versus bulk superconductivity

R. J. Papoular; G. Collin

doi:10.1103/PhysRevB.38.768

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Polarized-neutron study of the YBa2Cu3O7 system: Granular versus bulk superconductivity

R. J. Papoular, G. Collin

DOI 10.1103/PhysRevB.38.768 · Physical Review B

T1

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Abstract

Neutron depolarization measurements have been carried out in order to investigate superconductivity in the YBa2Cu3O7−x system on both powdered and sintered polycrystalline samples. This technique provides indirect evidence of superconductivity through magnetic-flux trapping in low fields as well as vortex-line penetration in higher fields. Powdered and sintered samples show markedly different behavior, probably connected to their granular nature: a sintered sample traps magnetic flux by developing shielding currents when a low magnetic field (<100 Oe) is removed after being applied below the superconducting temperature Tc, whereas a powder does not. Tc can be well determined (about 90 K) whereas Hc1(T) can only be estimated.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
YBa2Cu3O7-x Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	90	Pressure not reported	unknown