The structure of liquid and amorphous hafnia

Leighanne C. Gallington, Yasaman Ghadar, Lawrie B. Skinner, J. K.Richard Weber, Sergey V. Ushakov, Alexandra Navrotsky, Alvaro Vazquez-Mayagoitia, Joerg C. Neuefeind, Marius Stan, John J. Low, Chris J. Benmore

Research output: Contribution to journalArticlepeer-review

14 Scopus citations

Abstract

Understanding the atomic structure of amorphous solids is important in predicting and tuning their macroscopic behavior. Here, we use a combination of high-energy X-ray diffraction, neutron diffraction, and molecular dynamics simulations to benchmark the atomic interactions in the high temperature stable liquid and low-density amorphous solid states of hafnia. The diffraction results reveal an average Hf-O coordination number of ~7 exists in both the liquid and amorphous nanoparticle forms studied. The measured pair distribution functions are compared to those generated from several simulation models in the literature. We have also performed ab initio and classical molecular dynamics simulations that show density has a strong effect on the polyhedral connectivity. The liquid shows a broad distribution of Hf-Hf interactions, while the formation of low-density amorphous nanoclusters can reproduce the sharp split peak in the Hf-Hf partial pair distribution function observed in experiment. The agglomeration of amorphous nanoparticles condensed from the gas phase is associated with the formation of both edge-sharing and corner-sharing HfO6,7 polyhedra resembling that observed in the monoclinic phase.

Original languageEnglish (US)
Article number1290
JournalMaterials
Volume10
Issue number11
DOIs
StatePublished - Nov 10 2017

Keywords

  • Amorphous materials
  • Hafnium oxide
  • Liquid structure
  • Molecular dynamics
  • Nanoparticles
  • Neutron diffraction
  • X-ray diffraction

ASJC Scopus subject areas

  • Materials Science(all)

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