Paramagnetic Meissner effect in Bi high-temperature superconductors

W. Braunisch; N. Knauf; V. Kataev; S. Neuhausen; A. Grütz; A. Kock; B. Roden; D. Khomskii; D. Wohlleben

doi:10.1103/PhysRevLett.68.1908

Paramagnetic Meissner effect in Bi high-temperature superconductors

W. Braunisch, N. Knauf, V. Kataev, S. Neuhausen, A. Grütz, A. Kock, B. Roden, D. Khomskii, and D. Wohlleben

Phys. Rev. Lett. 68, 1908 – Published 23 March 1992

Abstract

For certain ceramic samples of the Bi-based high-temperture superconductors, the dc-field-cooling signal becomes paramagnetic in fields below a few 100 mOe. This effect correlates with an anomaly in the low-field microwave absorption. The data are consistent with orbital paramagnetic moments due to the appearance of spontaneous supercurrents in fields smaller than the lower critical field $H_{c 1 a}$ parallel to the CuO planes.