Inorganic capping material for ZnO quantum dots (QDs) was designed on the basis of the crystal and electronic structures, and a ternary beta-LiGaO2 was proposed as a candidate. Two reaction routes to the beta-LiGaO2 nanocrystals (NCs), the alkylhalide elimination reaction between gallium iso-propoxide and lithium bromide and the thermolysis of gallium and lithium acetylacetonates, were investigated. The alkylhalide elimination reaction resulted in near-stoichiometric beta-LiGaO2 NCs; however, it was not applicable to fabricate composite NCs with ZnO, because ZnO dissolved in the beta-LiGaO2 reaction solution upon heating. Based on the thermolysis formation of beta-LiGaO2, composite NCs of ZnO with beta-LiGaO2 were successfully obtained. The high resolution transmission electron microscopy and X-ray photoelectron spectroscopy results indicated that the composite was a ZnO/LiGaO2 core/shell nanostructure consisting of similar to 3.5 nm diameter core ZnO and similar to 0.5 nm thick beta-LiGaO2 shell layers. Because the photoluminescence of the core/shell QDs was dominated by the core ZnO, the type-I quantum well structure of the core/shell QDs, in which the core ZnO part forms the potential well, was strongly suggested. (C) 2011 Elsevier B.V. All rights reserved.