Crystal structures, elastic properties, and hardness of high-pressure synthesized CrB2 and CrB4

S. Wang, X. Yu, J. Zhang, Y. Zhang, L. Wang, Kurt Leinenweber, H. Xu, D. Popov, C. Park, W. Yang, D. He, Y. Zhao

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

Chromium tetraboride (CrB4), a recently proposed candidate for superhard materials, has been synthesized at high pressure and temperature by a solid-state reaction. As a byproduct, chromium diboride (CrB2) also forms and co-exists with CrB4 in the final product. The comparative studies of crystal structure, elastic property, and hardness of both phases have been conducted at the same sample environment conditions. The crystal structure of CrB4 has been refined with an orthorhombic symmetry of Immm(space group no. 71) or Pnnm (space group no. 58) using X-ray diffraction data. Further simulations indicate that the structural distinction between Immm and Pnnm can be resolved by neutron diffraction, due to the high scattering cross-section of boron (11B) by neutrons. Although CrB2 and CrB4 have close bulk modulus at about 230 GPa, the measured asymptotic Vickers hardness yields 16 GPa for CrB2 but 30 GPa for CrB4, which is nearly two times that of CrB2. The dramatic enhancement in hardness in CrB4 is attributed to the strong three-dimensional Cr-B network, in contrast to the layered lattice structure of hexagonal CrB2.

Original languageEnglish (US)
Pages (from-to)279-287
Number of pages9
JournalJournal of Superhard Materials
Volume36
Issue number4
DOIs
StatePublished - Jan 1 2014

Fingerprint

Chromium
Crystal structure
Hardness
Boron
Vickers hardness
Neutron diffraction
Solid state reactions
Byproducts
Neutrons
Elastic moduli
Scattering
X ray diffraction
Temperature

Keywords

  • chromium borides
  • compressibility
  • high-pressure synthesis
  • structure
  • superhard material.

ASJC Scopus subject areas

  • Materials Science(all)
  • Inorganic Chemistry

Cite this

Crystal structures, elastic properties, and hardness of high-pressure synthesized CrB2 and CrB4 . / Wang, S.; Yu, X.; Zhang, J.; Zhang, Y.; Wang, L.; Leinenweber, Kurt; Xu, H.; Popov, D.; Park, C.; Yang, W.; He, D.; Zhao, Y.

In: Journal of Superhard Materials, Vol. 36, No. 4, 01.01.2014, p. 279-287.

Research output: Contribution to journalArticle

Wang, S, Yu, X, Zhang, J, Zhang, Y, Wang, L, Leinenweber, K, Xu, H, Popov, D, Park, C, Yang, W, He, D & Zhao, Y 2014, 'Crystal structures, elastic properties, and hardness of high-pressure synthesized CrB2 and CrB4 ', Journal of Superhard Materials, vol. 36, no. 4, pp. 279-287. https://doi.org/10.3103/S1063457614040066
Wang, S. ; Yu, X. ; Zhang, J. ; Zhang, Y. ; Wang, L. ; Leinenweber, Kurt ; Xu, H. ; Popov, D. ; Park, C. ; Yang, W. ; He, D. ; Zhao, Y. / Crystal structures, elastic properties, and hardness of high-pressure synthesized CrB2 and CrB4 In: Journal of Superhard Materials. 2014 ; Vol. 36, No. 4. pp. 279-287.
@article{e968f8fb434b48d6bec716e52c9e160d,
title = "Crystal structures, elastic properties, and hardness of high-pressure synthesized CrB2 and CrB4",
abstract = "Chromium tetraboride (CrB4), a recently proposed candidate for superhard materials, has been synthesized at high pressure and temperature by a solid-state reaction. As a byproduct, chromium diboride (CrB2) also forms and co-exists with CrB4 in the final product. The comparative studies of crystal structure, elastic property, and hardness of both phases have been conducted at the same sample environment conditions. The crystal structure of CrB4 has been refined with an orthorhombic symmetry of Immm(space group no. 71) or Pnnm (space group no. 58) using X-ray diffraction data. Further simulations indicate that the structural distinction between Immm and Pnnm can be resolved by neutron diffraction, due to the high scattering cross-section of boron (11B) by neutrons. Although CrB2 and CrB4 have close bulk modulus at about 230 GPa, the measured asymptotic Vickers hardness yields 16 GPa for CrB2 but 30 GPa for CrB4, which is nearly two times that of CrB2. The dramatic enhancement in hardness in CrB4 is attributed to the strong three-dimensional Cr-B network, in contrast to the layered lattice structure of hexagonal CrB2.",
keywords = "chromium borides, compressibility, high-pressure synthesis, structure, superhard material.",
author = "S. Wang and X. Yu and J. Zhang and Y. Zhang and L. Wang and Kurt Leinenweber and H. Xu and D. Popov and C. Park and W. Yang and D. He and Y. Zhao",
year = "2014",
month = "1",
day = "1",
doi = "10.3103/S1063457614040066",
language = "English (US)",
volume = "36",
pages = "279--287",
journal = "Journal of Superhard Materials",
issn = "1063-4576",
publisher = "Allerton Press Inc.",
number = "4",

}

TY - JOUR

T1 - Crystal structures, elastic properties, and hardness of high-pressure synthesized CrB2 and CrB4

AU - Wang, S.

AU - Yu, X.

AU - Zhang, J.

AU - Zhang, Y.

AU - Wang, L.

AU - Leinenweber, Kurt

AU - Xu, H.

AU - Popov, D.

AU - Park, C.

AU - Yang, W.

AU - He, D.

AU - Zhao, Y.

PY - 2014/1/1

Y1 - 2014/1/1

N2 - Chromium tetraboride (CrB4), a recently proposed candidate for superhard materials, has been synthesized at high pressure and temperature by a solid-state reaction. As a byproduct, chromium diboride (CrB2) also forms and co-exists with CrB4 in the final product. The comparative studies of crystal structure, elastic property, and hardness of both phases have been conducted at the same sample environment conditions. The crystal structure of CrB4 has been refined with an orthorhombic symmetry of Immm(space group no. 71) or Pnnm (space group no. 58) using X-ray diffraction data. Further simulations indicate that the structural distinction between Immm and Pnnm can be resolved by neutron diffraction, due to the high scattering cross-section of boron (11B) by neutrons. Although CrB2 and CrB4 have close bulk modulus at about 230 GPa, the measured asymptotic Vickers hardness yields 16 GPa for CrB2 but 30 GPa for CrB4, which is nearly two times that of CrB2. The dramatic enhancement in hardness in CrB4 is attributed to the strong three-dimensional Cr-B network, in contrast to the layered lattice structure of hexagonal CrB2.

AB - Chromium tetraboride (CrB4), a recently proposed candidate for superhard materials, has been synthesized at high pressure and temperature by a solid-state reaction. As a byproduct, chromium diboride (CrB2) also forms and co-exists with CrB4 in the final product. The comparative studies of crystal structure, elastic property, and hardness of both phases have been conducted at the same sample environment conditions. The crystal structure of CrB4 has been refined with an orthorhombic symmetry of Immm(space group no. 71) or Pnnm (space group no. 58) using X-ray diffraction data. Further simulations indicate that the structural distinction between Immm and Pnnm can be resolved by neutron diffraction, due to the high scattering cross-section of boron (11B) by neutrons. Although CrB2 and CrB4 have close bulk modulus at about 230 GPa, the measured asymptotic Vickers hardness yields 16 GPa for CrB2 but 30 GPa for CrB4, which is nearly two times that of CrB2. The dramatic enhancement in hardness in CrB4 is attributed to the strong three-dimensional Cr-B network, in contrast to the layered lattice structure of hexagonal CrB2.

KW - chromium borides

KW - compressibility

KW - high-pressure synthesis

KW - structure

KW - superhard material.

UR - http://www.scopus.com/inward/record.url?scp=84906653067&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84906653067&partnerID=8YFLogxK

U2 - 10.3103/S1063457614040066

DO - 10.3103/S1063457614040066

M3 - Article

AN - SCOPUS:84906653067

VL - 36

SP - 279

EP - 287

JO - Journal of Superhard Materials

JF - Journal of Superhard Materials

SN - 1063-4576

IS - 4

ER -