Magnetic Phase Diagrams Of Electron-Doped High-T-C Cuprates Pr1-Xlacexcuo4-Delta And Nd2-Xcexcuo4-Delta Studied By Mu Sr Measurements

Magnetic phase diagrams of electron-doped high-temperature superconducting (SC) cuprates Nd2-xCexCuC4-delta (NCCO) and Pr1-xLaCexCuO4-delta (PLCCO) has been studied by means of muon spin relaxation and rotation (muSR) measurements. Two characteristic temperatures T-N1 and T-N2 are defined in the zero-field muSR (ZF-muSR) measurements for both NCCO and PLCCO. Below T = T-N1, which approximately corresponds to the previously reported Neel temperature, an exponential type muon spin relaxation firstly appears in the time spectra and upon cooling below around TN2 another faster component of relaxation or muon spin rotation is observed similarly. Although critical concentration for the bulk superconductivity is different between the two systems, antiferromagnetic (AF) phase contacts with the SC phase partially overlapping in both systems and AF phase is suddenly reduced in the appearance of SC phase, suggesting a competition between superconductivity and AF order. Our quantitative analyses of the AF volume fraction clearly demonstrate this. (C) 2002 Published by Elsevier Science B.V.