Premier cas de maladie de Kikuchi chez un patient infecté par le VIH

The crystal structure of perovskite based Ba(Ce0.8Zr0.2)O3 has been determined by X-ray and neutron powder diffractions. The space group has been established by Rietveld refinement. Our final analysis indicates that the space group of Ba(Ce0.8Zr0.2)O3 is Imma with an anti-phase oxygen octahedral tilting along the two crystallographic axes. At a temperature above the transition, 1273 K, the high temperature prototype phase is found to be cubic Pm3̄m.