Paramagnetic Meissner effect in conventional Nb superconductors

Journal Article · Fri Nov 01 04:00:00 EST 1996 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1007/BF00768436· OSTI ID:457207

Thompson, D J; Wenger, L E; Chen, J T ^[1]

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1. Wayne State Univ., Detroit, MI (United States)

The paramagnetic Meissner effect (PME), in which the field-cooled-magnetization (FCM) of superconducting samples is positive below the superconducting transition temperature T{sub c}, has been observed in certain ceramic and single-crystal samples of the high-T{sub c} cuprate superconductors and more recently in disk-shaped Nb samples. Through systematic investigations of the conditions for observing the PME in Nb disks, various surface treatments to the Nb disks were found to change both the zero-field-cooled-magnetization (ZFCM) and the FCM, including the appearance of a positive FCM in samples previously not exhibiting the PME as well as the elimination of the PME through surface abrasion. These results suggest that the PME arises from the field distributions created by the flux pinning associated with microstructural defects on the surface layer of the disk.

• Sponsoring Organization: USDOE
• OSTI ID: 457207
• Report Number(s): CONF-960808--; CNN: Grant F49620-93-1-0321
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 3-4 Vol. 105; ISSN JLTPAC; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
COPPER OXIDES
DEFECTS
MAGNETIC FLUX
MEISSNER-OCHSENFELD EFFECT
NIOBIUM
PARAMAGNETISM
SURFACE TREATMENTS