MAGNETIC-FLUX DISTRIBUTION AROUND BI2212 SUPERCONDUCTING SINGLE-CRYSTAL - THE PARAMAGNETIC-RESONANCE TECHNIQUE

The profile of the magnetic field distribution over the surface of Bi2 212 superconducting samples is studied by scanning with an electron pa ramagnetic resonance (EPR) microprobe. The magnetic held distribution is mapped from the measurements of the spin probe EPR-signal shift. Th e investigations were carried out for both zero field cooling and fiel d cooling procedures and showed different profile shapes in reversible and irreversible magnetization ranges of the superconducting material . It has been found that this method is particularly suitable to study the field profiles above the sample surface where other techniques ar e not so successful. (C) 1998 American Institute of Physics. [S0021-89 79(98)00615-X].