The structure of the Bi-doped pyrochlore, Bi0.5Nd1.5Ru2O7 has been studied
between 20 and 300 K using powder synchrotron diffraction methods. The stru
cture shows an abupt change in the Bi(Nd)-O and and Ru-O contacts near 200
K as a consequence of a metal-semiconductor transition. There is a marked h
ysteresis in the structural parameters upon rewarming the sample. (C) 1999
Academic Press.