We confirm the recent finding of a paramagnetic Meissner effect on melt-processed ${\mathrm{Bi}}_2$${\mathrm{Sr}}_2$${\mathrm{CaCu}}_2$${\mathrm{O}}_8$ ceramics: on cooling in fields below 200 mG, the samples show a magnetization that is parallel to the applied field. It is shown that the sum rule for the remanent magnetization remains valid in this field range, yielding an absolute value of the remanent magnetization that exceeds the value of the zero-field-cooled magnetization. This observation is discussed in terms of unconventional vortices and current loops. It is argued that the effect is not due to paramagnetic impurities.

• Received 13 August 1992

DOI:https://doi.org/10.1103/PhysRevB.47.8331