The relationship between structure and conductivity was investigated in the (BIMEVOX) system, Bi2V1-xCoxO5.5-3x/2 where x was between 0.07 and 0.25, by using alternating-current impedance spectroscopy, X-ray and neutron diffraction techniques. The Arrhenius plots comprised 2 straight line segments; one at temperatures below 450C and one at temperatures above 550C. Three types of behavior were observed, in the intermediate region, which appeared to be composition-dependent. All of the samples exhibited changes in conductivity after a first heating cycle, but this hysteresis persisted only for compositions below x = 0.10.

F.Krok, I.Abrahams, D.G.Bangobango, W.Bogusz, J.A.G.Nelstrop: Solid State Ionics, 1996, 86-88[1], 261-6