High-Resolution Powder Neutron Diffraction Study of Nd1.93Ce0.07CuO4-δ. No Evidence for Phase Separation at this Composition

Abstract

Very high-resolution powder neutron diffraction has been employed to study the crystal structure of the T' phase Nd1.93Ce0.07CuO4-δ at room temperature. No evidence for multiphase composition is found at this resolution and a single phase model based on the tetragonal I4/mmm space group is in excellent agreement with the experimental data. It appears that the possible occurrence of phase separation at higher dopant levels may be related to the metal-insulator transition which occurs close to the onset of superconductivity and after the long-range antiferromagnetic order is destroyed.