High-resolution powder neutron diffraction study of ndi.93ceo.o7cu0₄_₈. no evidence for phase separation at this composition.

Very high-resolution powder neutron diffraction has been employed to study the crystal structure of the T phase Ndi.9₈Ce₀.07CuO4_i at room temperature. No evidence for multiphase composition is found at this resolution and a single phase model based on the tetragonal M/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.