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Title: Mechanical behaviors and phase transition of Ho2O3 nanocrystals under high pressure

Authors:
; ; ; ;
Publication Date:
Research Org.:
Energy Frontier Research Centers (EFRC); Energy Frontier Research in Extreme Environments (EFree)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1210833
DOE Contract Number:
SC0001057
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Appl. Phys.; Journal Volume: 116; Related Information: EFree partners with Carnegie Institution of Washington (lead); California Institute of Technology; Colorado School of Mines; Cornell University; Lehigh University; Pennsylvania State University
Country of Publication:
United States
Language:
English
Subject:
catalysis (heterogeneous), solar (photovoltaic), phonons, thermoelectric, energy storage (including batteries and capacitors), hydrogen and fuel cells, superconductivity, charge transport, mesostructured materials, materials and chemistry by design, synthesis (novel materials)

Citation Formats

Yan, Xiaozhi, Ren, Xiangting, He, Duanwei, Chen, Bin, and Yang, Wenge. Mechanical behaviors and phase transition of Ho2O3 nanocrystals under high pressure. United States: N. p., 2014. Web. doi:10.1063/1.4890341.
Yan, Xiaozhi, Ren, Xiangting, He, Duanwei, Chen, Bin, & Yang, Wenge. Mechanical behaviors and phase transition of Ho2O3 nanocrystals under high pressure. United States. doi:10.1063/1.4890341.
Yan, Xiaozhi, Ren, Xiangting, He, Duanwei, Chen, Bin, and Yang, Wenge. Mon . "Mechanical behaviors and phase transition of Ho2O3 nanocrystals under high pressure". United States. doi:10.1063/1.4890341.
@article{osti_1210833,
title = {Mechanical behaviors and phase transition of Ho2O3 nanocrystals under high pressure},
author = {Yan, Xiaozhi and Ren, Xiangting and He, Duanwei and Chen, Bin and Yang, Wenge},
abstractNote = {},
doi = {10.1063/1.4890341},
journal = {J. Appl. Phys.},
number = ,
volume = 116,
place = {United States},
year = {Mon Jul 21 00:00:00 EDT 2014},
month = {Mon Jul 21 00:00:00 EDT 2014}
}
  • Mechanical properties and phase transition often show quite large crystal size dependent behavior, especially at nanoscale under high pressure. Here, we have investigated Ho2O3 nanocrystals with in-situ x-ray diffraction and Raman spectroscopy under high pressure up to 33.5 GPa. When compared to the structural transition routine cubic -> monoclinic -> hexagonal phase in bulk Ho2O3 under high pressure, the nano-sized Ho2O3 shows a much higher onset transition pressure from cubic to monoclinic structure and followed by a pressure-induced-amorphization under compression. The detailed analysis on the Q (Q = 2π/d) dependent bulk moduli reveals the nanosized Ho2O3 particles consist of amore » clear higher compressible shell and a less compressible core. Insight into these phenomena shed lights on micro-mechanism studies of the mechanical behavior and phase evolution for nanomaterials under high pressure, in general.« less
  • Mechanical properties and phase transition often show quite large crystal size dependent behavior, especially at nanoscale under high pressure. Here, we have investigated Ho{sub 2}O{sub 3} nanocrystals with in-situ x-ray diffraction and Raman spectroscopy under high pressure up to 33.5 GPa. When compared to the structural transition routine cubic -> monoclinic -> hexagonal phase in bulk Ho{sub 2}O{sub 3} under high pressure, the nano-sized Ho{sub 2}O{sub 3} shows a much higher onset transition pressure from cubic to monoclinic structure and followed by a pressure-induced-amorphization under compression. The detailed analysis on the Q (Q = 2π/d) dependent bulk moduli reveals the nanosized Ho{sub 2}O{submore » 3} particles consist of a clear higher compressible shell and a less compressible core. Insight into these phenomena shed lights on micro-mechanism studies of the mechanical behavior and phase evolution for nanomaterials under high pressure, in general.« less
  • The high pressure induced phase transitions in Zn{sub 1-x} Cu{sub x} O (x = 0.005 and 0.011) are investigated by angle-dispersive synchrotron radiation X-ray diffraction. As the pressure increases, phase transformations from the wurtzite structure to the rocksalt structure are observed in both samples, with the transition pressures at 9.8 GPa and 7.9 GPa, respectively. With the increasing of the Cu-doping concentration in ZnO, crystalline parameters, the bulk moduli, and the Zn-O bond lengths all increased, meanwhile, the transition pressures decreased. The results could be explained in terms of the reduction of phase transformation barriers and the lowering of bondmore » energy.« less
  • We synthesized a cubic BC{sub 3} (c-BC{sub 3}) phase, by direct transformation from graphitic phases at a pressure of 39 GPa and temperature of 2200 K in a laser-heated diamond anvil cell. A combination of x-ray diffraction, electron diffraction, transmission electron microscopy (TEM) imaging, and electron energy loss spectroscopy (EELS) measurements lead us to conclude that the obtained phase is hetero-nano-diamond, c-BC{sub 3}. High-resolution TEM imaging of the c-BC{sub 3} specimen recovered at ambient conditions demonstrates that the c-BC{sub 3} is a single, uniform, nanocrystalline phase with a grain size of about 3-5 nm. The EELS measurements show that themore » atoms inside the cubic structure are bonded by sp{sup 3} bonds. The zero-pressure lattice parameter of the c-BC{sub 3} calculated from diffraction peaks was found to be a = 3.589 {+-} 0.007 {angstrom}. The composition of the c-BC{sub 3} is determined from EELS measurements. The ratio of carbon to boron, C/B, is approximately 3 (2.8 {+-} 0.7).« less