skip to main content

DOE PAGESDOE PAGES

Title: The Structure of Liquid and Amorphous Hafnia

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 HfO 6,7 polyhedra resembling that observed in the monoclinic phase.
Authors:
 [1] ;  [2] ;  [1] ;  [1] ;  [3] ;  [3] ;  [2] ;  [4] ;  [5] ;  [6] ;  [1]
  1. Argonne National Lab. (ANL), Argonne, IL (United States). X-ray Science Division
  2. Argonne National Lab. (ANL), Argonne, IL (United States). Argonne Leadership Computing Facility
  3. Univ. of California, Davis, CA (United States). Peter A. Rock Thermochemistry Lab. NEAT ORU
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Chemical and Engineering Materials Division
  5. Argonne National Lab. (ANL), Argonne, IL (United States). Global Security Sciences
  6. Argonne National Lab. (ANL), Argonne, IL (United States). Computing, Environment and Life Sciences
Publication Date:
Grant/Contract Number:
AC02-06CH11357; 1506229
Type:
Accepted Manuscript
Journal Name:
Materials
Additional Journal Information:
Journal Volume: 10; Journal Issue: 11; Journal ID: ISSN 1996-1944
Publisher:
MDPI
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Univ. of California, Davis, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); ANL Laboratory Directed Research and Development (LDRD) Program; National Science Foundation (NSF)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; X-ray diffraction; neutron diffraction; molecular dynamics; liquid structure; amorphous materials; nanoparticles; hafnium oxide
OSTI Identifier:
1422595