Defects in Metal Oxide Nanoparticle Powders

Abstract

Metal oxides are mainly used in powder or particulate form for their application as functional materials. Insights into functional as well as unwanted properties of different defect types ranging from oxygen vacancies to grain boundaries and pores require an integrated characterization approach and are extremely difficult to establish. After a brief introduction into the complexity of particle systems and related heterogeneities, we discuss examples where for defects and other distinct structural features of MgO or TiO 2 particle systems firm structureproperty relationships have been established. Moreover, we want to point out that processing of particle matters. Related microstructural changes can induce the formation of solid-solid interfaces upon transformation of nanoparticle powders into mesoporous nanoparticle networks. This change in aggregation level and microstructure can substantially modify the electronic, optical and spectroscopic properties of metal oxide nanoparticle ensembles and, for this reason, plays a critical role for the generation of structural and-at the same time-functional defects inside particle ensembles. Introduction Particle Systems and the Hierarchy of DefectsLarge quantities of metal oxide particle powders are widely used in materials science and employed in very diverse areas such as engineering [1] catalysis [2] electronics [3][4][5] and energy technology [6]. The behavior of a metal oxide powder

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