FAST IONIC-CONDUCTIVITY AND CRYSTAL-STRUCTURE OF SPINEL-TYPE LI2-XMN1-XMXCL4 (M=GA,IN)

The phase relationships of the quaternary systems LiCl-MnCl2-GaCl3 and LiCl-MnCl2-InCl3 as well as LiCl-CdCl2-(MCl3)-Cl-III (M-III = Ga, In, Fe, Al) have been studied by X-ray and Raman spectroscopic experiment s. The crystal structures of spinel-type Li1.9Mn0.9Ga0.1Cl4 and Li1.65 Mn0.65In0.35Cl4 have been determined by X-ray powder and X-ray single- crystal studies, respectively. The gallium and indium ions occupy octa hedral sites of the spinel structure as shown by both the spectroscopi c and the structure studies. As novel quaternary compounds isotypic (L iMInCl6)-In-II (M-II = Mg, Mn, Fe, Co, Cd) have been established. The electric conductivity of spinel-type solid solutions (Li2-xMn1-xMxCl4) -Cl-III (M-III = Ga, In), which are fast ionic conducting materials, d ecreases with increasing In3+ content, but partly increases with highe r Ga3+ content. The two-phase material Li1.7Mn0.7Ga0.3Cl4 displays an ionic conductivity of 6.4 x 10(-2) Omega(-1) cm(-1) even at 200 degree s C.