Structural and electrical consequences of high dopant levels in the BIMGVOX system

The influence of high Mg2+ dopant levels in BIMGVOX, Bi2MgxV1-xO5.5-3x/2 (0 .05 less than or equal tox less than or equal to0.40) on structure and cond uctivity has been investigated using X-ray powder diffraction and a.c. impe dance spectroscopy. Four, compositionally dependent. structural ranges are observed at room temperature, with emergence of a new orthorhombic phase at high dopant levels. Generally the Arrhenius plots of conductivity show two linear regions the limits of which an compositionally dependent. The resul ts have been correlated to the stability ranges of various polymorphs withi n the system. (C) 2000 Elsevier Science B.V. All rights reserved.