Phase equilibria and crystal structure relationships in the ternary Li–B–C system
Abstract
Phase equilibria in the Li–B–C ternary system have been investigated by X-ray powder diffraction, scanning electron microscopy, electron probe microanalysis and differential scanning calorimetry. The isothermal section of the phase diagram has been constructed over the whole concentration range at 400 °C. The Li–B–C system is characterized by the formation of six ternary compounds: τ1 – LiBC3, τ2 – LiB2C2, τ3 – LiBC, τ4 – Li2B2C, τ5 – LiB6C and τ6 – LiB13C2. The formation of the new ternary compound LiB2C2 (own structure type, space group P63/mmc, a = 2.5930(3) Å, c = 22.680(1) Å) and binary BC3 (space group Pm2, a = 2.4588(4) Å, c = 6.770(2) Å) has been revealed. The crystal structures are discussed in the light of the underlying graphene and heterographene networks.