skip to main content

DOE PAGESDOE PAGES

Title: Combined Theoretical and in Situ Scattering Strategies for Optimized Discovery and Recovery of High-Pressure Phases: A Case Study of the GaN–Nb 2O 5 System

The application of pressure in solid-state synthesis provides a route for the creation of new and exciting materials. However, the onerous nature of high-pressure techniques limits their utility in materials discovery. The systematic search for novel oxynitrides—semiconductors for photocatalytic overall water splitting—is a representative case where quench high-pressure synthesis is useful and necessary in order to obtain target compounds. In this paper, we utilize state of the art crystal structure prediction theory (USPEX) and in situ synchrotron-based X-ray scattering to speed up the discovery and optimization of novel compounds using high-pressure synthesis. Using this approach, two novel oxynitride phases were discovered in the GaN–Nb 2O 5 system. The (Nb 2O 5) 0.84:(NbO 2) 0.32:(GaN) 0.82 rutile structured phase was formed at 1 GPa and 900°C and gradually transformed to a α-PbO 2-related structure above 2.8 GPa and 1000°C. The low-pressure rutile type phase was found to have a direct optical band gap of 0.84 eV and an indirect gap of 0.51 eV.
Authors:
 [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Stony Brook Univ., NY (United States). Department of Geosciences
  2. Stony Brook Univ., NY (United States). Dept. of Physics and Astronomy
  3. Stony Brook Univ., NY (United States). Department of Materials Science and Engineering
  4. Stony Brook Univ., NY (United States). Mineral Physics Institute
  5. Stony Brook Univ., NY (United States). Department of Geosciences, Mineral Physics Institute, and Department of Chemistry; Brookhaven National Lab. (BNL), Upton, NY (United States). Photon Sciences
Publication Date:
Report Number(s):
BNL-112567-2016-JA
Journal ID: ISSN 0020-1669
Grant/Contract Number:
SC00112704; AC02-98CH10886; AC02-06CH11357; AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Inorganic Chemistry
Additional Journal Information:
Journal Volume: 55; Journal Issue: 7; Journal ID: ISSN 0020-1669
Publisher:
American Chemical Society (ACS)
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; High-pressure Synthesis; Materials Discovery; Photocatylictic Water Splitting; Oxynitrides; Crystal Structure Prediction
OSTI Identifier:
1340381