DIFFUSE SCATTERING OF THE LITHIUM BORIDE Li_xB

M. Wörle, R. Nesper

Laboratorium für anorganische Chemie, ETH Zürich, Universitätstr. 6, CH-8092 Zürich, Switzerland

Keywords: lithium boride, diffuse scattering, Rietveld refinement

The lithium boride with the composition Li_xB (0.667 < x < 1.22) contains linear boron chains embedded and stabilized in a lithium matrix. A simultaneous Rietveld refinement of Xray and neutron diffraction powder data revealed, that the chains are disordered along the chain direction, giving rise to areas of diffuse intensity in the corresponding Xray and neutron powder diffraction patterns. The average boron-boron distance is not commensurate with the lithium matrix. The diffuse intensity in this system was simulated and the bonding situation in the boron chains was investigated by means of theoretical and spectroscopical methods.

a) Electron density distribution in Li_xB and b) experimental and simulated neutron powder diffraction pattern with diffuse scattering.