PARAMAGNETISM IN COPPER MONOXIDE SYSTEMS

This paper describes the problem of high-temperature superconductivity related to investigations of the magnetic susceptibility, electron pa ramagnetic resonance, and O K alpha x-ray emission spectra of samples from the following systems based on copper monoxide: CuO-Cu, CuO-Cu2O and CuO-MgO. In all these systems, thermal processing results in a par amagnetism which is not observed in the individual components of these systems before they are processed. O K alpha spectra of the interface of a Cu-single-crystal CuO film structure indicate the presence of no t only Cu2+ but also Cu1+ ions in the layer of CuO in close contact wi th Cu. Possible reasons for the appearance of paramagnetism in these s ystems are discussed. It is proposed that a paramagnetic layer at the contact between the antiferromagnetic copper monoxide and the other co pper-oxide phases or with copper could be the cause of the impurity me tastability observed previously in the high-T-c superconducting phase. O 1998 American Institute of Physics.