ON THE STRUCTURE AND PROPERTIES OF THE LAYERED LANTHANIDE (LN) BARIUMCOPPER OXYBORATES, LNBACUO(2)BO(3)

An ordered structure model has been derived for the new series of laye red lanthanide (Ln) cuprates, LnBaCuO(2)BO(3), and some of its members have been synthesized. The cuprates were prepared under ambient press ure by reacting BaO2, Ln(2)O(3), CuO and B2O3 at 1190 K. The derived m odel, with the tetragonal space-group symmetry P4bm and a = 5.5743 (4) , c = 7.5053 (6) Angstrom for the La compound, has been successfully t ested against X-ray powder diffraction data. The model has reasonable estimated bond-valence values. Measured magnetic susceptibilities of p owder specimens of LaBaCuO2BO3 indicate a transition to a diamagnetic state at ca 29 K.