The investigation of EPR paramagnetic probe line width and shape temperature dependence in high-temperature superconductors of Bi-Pb-Sr-Ca-Cu-O system

The work describes the appearance of magnetic phases in the strongly anisotropic high-temperature superconductor Bi1.7Pb0.3Sr2Ca2Cu3O10 − δ, in the temperature region where the superconductor is in the normal state, as determined by the EPR line width, ΔH of a paramagnetic probe in its proximity. In the normal state, near 175K>Tc a peak in the temperature dependence of ΔH develops with the characteristic time ∼17 min, which indicates the onset of a magnetic phase-domains in this material.