Abstract
We observed the specific structures of molecular alignments in the liquid crystal mixtures of nalkylcyanobiphenyl (mCB: m=8, 10 and 12) on highly oriented pyrolytic graphite (HOPG) substraies by a scanning tunneling microscope (STM). 8CB-10CB mixtures' alignments, which were quite different from already reported alignments for each monophase 8CB and 10CB, showed two types of alignments and packings of both molecules depending on the mixing rate of 8CB and 10CB. One was observed in the mixture with rather low mixing rate of 8CB in 10CB in which a unit structure was composed of two 8CB molecules and four 10CBs with bilayer conformation. Another formed a unit structure that consisted of four 8CBs and of six 10CB molecules in the mixture with rather high concentration of 8CB. No other combination was observed. 10CB-12CB mixtures also showed characteristic structueres.
