Structural and transport properties of the BaBi1-xInxO3 system

The structures of In-doped perovskites BaB1-xInxO3, 0 less than or equal to x less than or equal to 0.5, have been investigated by powder X-ray and ne utron diffraction. Two phase transitions were observed. As the In concentra tion is increased, the parent monoclinic BaBiO3 first loses the breathing-m ode distortions (x approximate to 0.1) and then changes the direction of oc tahedral tilts (x approximate to 0.4), resulting in the orthorhombic (Ibmm) and tetragonal (I4/mcm) symmetry, respectively, with random arrangement of Bi(III) and Bi(V) ions. The transport measurements show an increase of con ductivity with increasing indium concentration, but the system remains semi conducting. (C) 2000 Elsevier Science Ltd. All rights reserved.