First, we have studied the stability of Sr2-xBaxCu3O4Cl2-yBry of the 2342 phase with the Cu3O4 plane, which is composed of the Cu(1)O2 and extra Cu(2) sublattices, in the temperature range between 600 and 950 °C. It has been found that a mixture of (Sr,Ba)2CuO2(Cl,Br)2 with the CuO2 plane and CuO becomes stable instead of the 2342 phase with the Cu3O4 plane for smaller values of x and y at low temperatures. Next, the electrical and magnetic properties of Sr2-xBaxCu3O4Cl2-yBry with the Cu3O4 plane have been investigated. The electrical resistivity exhibits semiconductive behavior. The magnetic susceptibility shows three-dimensional antiferromagnetic order below TN(1) = 300-400 K and TN(2) to approximately 30 K for the Cu(1) and Cu(2) sublattices, respectively. A broad peak due to the two-dimensional antiferromagnetic order in the Cu(2) sublattice is also observed around TN2D(2) = 100 K. With increasing x and y, the lattice parameters increase, the electrical resistivity increases and values of both TN(1) and TN2D(2) decrease. These results are explained as being due to the decrease of the overlaps between Cu3d and O2p, Cl3p, Br4p orbits.
|Number of pages||5|
|Journal||Funtai Oyobi Fummatsu Yakin/Journal of the Japan Society of Powder and Powder Metallurgy|
|Publication status||Published - 1999 Sept|