The static magnetic susceptibility of two different YBa2Cu3O6.30 samples has been measured at different fields in the range 2 - 300 K, using a superconducting quantum interference device magnetometer; one sample has been prepared by oxygen intercalation, the other one by deintercalation. The susceptibility shows a peak near 45 K in both samples, which depends on the field and the magnetic history. The susceptibility of semiconducting and superconducting compounds, with an oxygen content O6.20 and O6.41, respectively, has also been investigated. The presence of the peak in the YBa2Cu3O6.30 samples has been explained by the combined effect of regions with a Curie-like behaviour and superconducting regions. The origin of these regions is discussed.
Alternating current magnetic susceptibility of a molecular magnet
submonolayer directly patterned onto a micro superconducting quantum interference
device