Controlled Impurity Admixture: From Doped Systems to Composites

Abstract

Solid solubility is often enhanced with decreasing particle size, which means that nanoparticles can be doped or alloyed with atoms or ions that show a miscibility gap on the bulk level under the same conditions. If the solubility limit is reached, the nanoparticles undergo phase segregation and form multicomponent or heterostructured nanomaterials. This chapter provides an overview of the different synthesis techniques for doped, alloyed and phase-segregated metal oxide nanoparticles. It begins with liquid-phase routes, proceed to gas-phase methods and then discusses solid-state approaches. The chapter presents examples, where phase-segregation or seeded growth leads to the formation of composite or multicomponent materials. It focuses clearly on the synthesis. In the case of doped nanoparticles, the precise incorporation of impurity atoms represents an additional experimental complication going well beyond simple compositional control.