X‐ray Powder Study of 2BaO·CuO

A compound of composition 2BaO·CuO was synthesized during the phase equilibrium study of the BaO‐Y 2 O 3 ‐CuO x system. Phase characterization has been carried out by using X‐ray powder diffraction. The crystal symmetry was found to be the same as that of Ca 2 CuO 3 and Sr 2 CuO 3 . It is orthorhombic with space group Immm and lattice parameters a=12.9655(14) Å (1.29655 nm), b=4.1007(3) Å (0.41007 nm), c=3.9069(5) Å (0.39069 nm), and V=207.72(3) Å 3 (0.20772 nm 3 ). The experimental pattern shows good agreement, in general, with intensity values calculated by assuming Ba 2 CuO 3 to have a structure similar to that of Sr 2 CuO 3 and Ca 2 CuO 3 . Intensity discrepancy for the h00 reflections might be due to preferred orientation.