STRUCTURAL-PROPERTIES OF DIPOLAR GLASS-II - KBR1-X(NO2)(X)

An x-ray diffraction study was performed to elucidate the structural p roperties of a dipolar glass, KBr1-x(NO2)(x). The strong diffuse scatt ering was observed below the glass transition temperature Tg near the Brillouin-zone center of an fee lattice, indicating the local distorti on of the lattice induced by the short-range ferroelectric order of ni trite ions. The integrated intensity of the diffuse scattering follows the Edwards-Anderson order parameter characterizing the glass transit ion. The temperature factor of bromine and potassium ions estimated fr om the x-ray structural analysis deviates from the Debye approximation below T-g, and the deviation also follows the Edwards-Anderson order parameter. The results indicate that the strong diffuse scattering is caused from the fluctuation of bromine and potassium ions with only sh ort-range ferroelectric correlation induced by the short-range order o f nitrite ions.