LNHAL2HN - NEW PHASES IN THE TERNARY-SYSTEM LN/HAL/H .1. STRUCTURES

Rare earth hydride halides of the compositions LaBr2(H, D)0.90, CeBr2H0.87, CeI2H0.90, CeI2D0.96, and GdI2H0.97 have been synthesised by heating either the dihalides, LnHal2, or mixtures of LnHal3 and LnH(x) at 700-degrees-C - 800-degrees-C in hydrogen atmosphere. The heavy atom partial structures, as determined by X-ray scattering, correspond to the various sequences found in MoS2 and NbS2. From neutron scattering experiments the hydrogen atoms were located in the positions centering the anionic prisms and the cationic triangles.