Nanocrystalline zinc aluminate (ZnAl2O4) particles with a spinel structure were prepared by hydrolyzing a mixture of aluminum chloride hexahydrate and zinc chloride in deionized water. It was found that pH value and reaction temperature play critical roles in the formation of nano-sized ZnAl2O4. Depending on pH values in the precursor solution, ZnAl layered double hydroxide (ZnAl-LDH), ZnO4 boehmite or gibbsite could be formed. At pH 7 and T>120 degreesC, the nanocrystalline ZnAl2O4 particles with average particle size of similar to5 am are easily synthesized through ZnAl layered double hydroxide (ZnAl-LDH). After surface treatment with R-OH by using the cationic surfactant CTAB, the ZnAl2O4/Eu core-shell structure can be developed. The ZnAl2O4/Eu core-shell structure can show both emissions from D-5(0) to F-7(2) sensitivity energy level and D-5(2) to F-7(0) depth energy level. (C) 2004 Elsevier B.V. All rights reserved.