Probing Magnetism of High-Tc Superconductor Y-Ba-Cu Oxide by Positive Muons

Abstract
Magnetic properties of a newly discovered high-T c superconductor, Y-Ba-Cu oxide, were studied by zero-field positive muon spin relaxation method in a zero external magnetic field. Some kind of a magnetic phase transition was found at a temperature between 10 K and 27 K. It is discussed how this magnetism relates to the superconductivity.