Tohru Ozawa

145 Å superstructure in Me∠(x+2)/3T∠(x−2)/3Ox (Me=Mg,Sc; T=Si,Mg)

By means of direct lattice imaging, a new structure type of Li‐free analogue of enstatite‐IV has been established. Unlike known structure type, it does not consist of the same kind of slabs but consists of unit slabs, each being a composite of the slabs of known structure types; the unit slab has a thickness of 72.5 A. The occurrence of such a structure may be due to slight shifts in chemical composition during crystallization. Diffuse reflections observed in diffraction patterns are caused by random stackings of known types of slabs as well; we did not observe any new types of slabs.