Divalent europium nanocrystals: controllable synthesis, properties, and applications

Magnetic and luminescent bifunctional divalent europium nanocrystals (Eu(2+) NCs) are a promising class of novel advanced materials that have various applications in magneto-optic devices, catalysis, bioimaging, and solar cells. In the past few decades, much work has been carried out to study the synthesis, properties, and applications of Eu(2+) NCs. The aim of this Minireview is to present the progress in preparing Eu(2+) NCs based on the reported research, by describing the advantages and disadvantages of the synthesis methods. The morphologies and size are controlled through adjusting the experimental conditions. Eu(2+) NCs show superior magnetic and luminescence properties simultaneously. Self-assembly and doping with other ions are important routes to improve their magnetic and luminescence properties. Their applications in magneto-optic devices are discussed. Some difficulties and challenges in the fabrication of Eu(2+) NCs are discussed, such as water-soluble Eu(2+) NCs and tunable luminescence in the whole visible region.