Core shell structure for solid gas synthesis of LiBD4

Abstract

The formation of LiBD₄ by the reaction of LiD in a diborane/hydrogen atmosphere was analysed by in situ neutron diffraction and subsequent microstructural and chemical analysis of the final product. The neutron diffraction shows that nucleation of LiBD₄ already starts at temperatures of 100 °C, i.e. in its low temperature phase (orthorhombic structure). However, even at higher temperatures the reaction is incomplete. We observe a yield of approximately 50% at a temperature of 185 °C. A core shell structure of the grains, in which LiBD₄ forms a passivation layer on the surface of the LiD grains, was found in the subsequent microstructural (electron microscopy) and chemical (electron energy loss spectrometry) analysis.