CRYSTAL AND MAGNETIC-STRUCTURES OF BI2CUO4

The crystal structure of Bi2CuO4 has been reinvestigated and its magnetic structure solved by neutron powder diffraction. The crystal structure, according to earlier work, is perfectly described in the space group P4/ncc. Contrary to the dimeric magnetic behaviour suggested in a recent paper, the title compound becomes long-range antiferromagnetically ordered below 50 K. The ground state has Cz symmetry and the crystallographic magnetic group is P4/n'c'c'. The magnetic moment of copper atoms at 1.5 K is 0.93(6) mu B, which is very close to the saturation moment of spin-only Cu(II)(d9).