Abstract

Size-dependent lattice expansion of nanoparticles is observed for many ionic compounds, including metal oxides, while lattice contraction prevails for pure metals. However, the physical origin of this effect, which is of importance for the thermodynamic, chemical and electronic properties of nanoparticles, is discussed controversially. After a survey of the experimental literature, revealing a wide variety of materials with size-dependent lattice expansion, we show that the negative surface stress is the key reason for lattice expansion, while the excess of lattice sums or point defects of various charge states can be excluded as general explanations. Ab initio calculations of surface stresses for various surface structures of metal oxides confirm the model of a surface-induced lattice expansion.

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Publisher Full Text

Authors

Diehm PM, Ágoston P, Albe K

Institution

TU Darmstadt, Institut für Materialwissenschaft, Fachgebiet Materialmodellierung, Petersenstr. 32, D-64287 Darmstadt, Germany. mdiehm@mm.tu-darmstadt.de

Source

Chemphyschem : a European journal of chemical physics and physical chemistry 13:10 2012 Jul 16 pg 2443-54

Pub Type(s)

Journal Article

Language

eng

PubMed ID

22730342