The crystal structures of Nd2CuO4 and superconducting Nd1.835Ce0.165CuO4 under hydrostatic pressure up to 0.6 GPa have been investigated by time-of-flight neutron powder diffraction with a He gas pressure cell. The a and c parameters and the volumes of the tetragonal unit cells decreased linearly with increasing pressure. The bulk moduli, K, are 134 GPa for Nd2CuO4 and 140 GPa for the Ce-doped sample. These K values lie between those of La1.85Sr0.15CuO4 and La1.82Ca1.18Cu2O6. The compressibilities along the c axes were about 1.5 times as large as those along the a axes. The linear compressibilities along the a and c axes and the bulk moduli were compared with those calculated on the basis of a simple compression model proposed by Cornelius et al. The negligible effect of pressure on the Tc of Nd2-xCexCuO4 is discussed in connection with the crystal data obtained in this study.
ASJC Scopus subject areas
- Condensed Matter Physics