The nano materials often exhibit very interesting electrical,optical,magnetic,and chemical properties,which can not be achieved by their bulk counterparts[1-7].The development of uniform nanometer sized particles has been intensively pursued because of their technological and fundamental scientific importance[8-15].It is significant that nanostructured materials can be controllably assembled into the required geometry onto substrates,becoming the basis of the next generation of components and devices[16-31].The development of new methods and strategies for organizing the nanoparticle basic building blocks into the desired structures is required.Superlattices made from these building blocks give us the opportunity to study not only the properties of the individual building blocks,but also collective effects.The superparamagnetic iron oxide nanocrystals(NCs) have been used in the fields of bio-medicine,ferrofluids,refrigeration system,catalysis,particularly in magnetic resonance imaging,tissue engineering,and drug delivery applications[32-42].