Room-temperature transition of rhombohedral-type boron nitride under high static pressure

Ueno, Masaki; Hasegawa, K.; Oshima, Ryuichiro; Onodera, Akifumi; Shimomura, Osamu; Takemura, Keiji; Nakae, Hiroyuki; Matsuda, T.; Hirai, Toshio

doi:10.1103/physrevb.45.10226

Cited by 44 publications

(28 citation statements)

References 11 publications

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“…In both cases there exists a simple structural relation between the ''parent'' and ''daughter'' phases (see the Appendix), and one can be transformed into the other by following a path involving the collective motion of layers of atoms. The experimental results suggest that, at room temperature, a displacive mechanism based on these distortions is a plausible model for the h-BN→w-BN and r-BN→c-BN transitions (see Ueno, Hasegawa, et al, 1992, and references therein). Compared with the gra→cd transition in C, the transition between the layered and dense structures in BN involves smaller activation energies, which is consistent with its larger heteropolarity (Wentzcovitch et al, 1988).…”

Section: Bnmentioning

confidence: 99%

High-pressure phases of group-IV, III–V, and II–VI compounds

et al. 2003

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Advances in the accuracy and efficiency of first-principles electronic structure calculations have allowed detailed studies of the energetics of materials under high pressures. At the same time, improvements in the resolution of powder x-ray diffraction experiments and more sophisticated methods of data analysis have revealed the existence of many new and unexpected high-pressure phases. The most complete set of theoretical and experimental data obtained to date is for the group-IVA elements and the group-IIIA-VA and IIB-VIA compounds. Here the authors review the currently known structures and high-pressure behavior of these materials and the theoretical work that has been done on them. The capabilities of modern first-principles methods are illustrated by a full comparison with the experimental data. CONTENTS

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Section: Bnmentioning

confidence: 99%

High-pressure phases of group-IV, III–V, and II–VI compounds

et al. 2003

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“…[1][2][3][4][5] In some cases, the material under study is compressed between two diamond anvils without any external support, [6][7][8] i.e., the external part of the sample serves as a gasket for the internal part, which is under high pressure. However, in most cases, [9][10][11][12][13][14] the sample is placed inside of a deformable gasket made of a material with different strength. If achieving maximum possible pressure in a reasonably large volume is the goal, the gasket is made of the strongest possible materials, such as T301 stainless steel, 13 rhenium, 10,15 and even diamond powder.…”

Section: Introductionmentioning

confidence: 99%

“…For example, the rhombohedral-to-cubic boron nitride (rBN-to-cBN) transformation under compression without hydrostatic media starts at 5.6 GPa, 8 while it takes place at 55 GPa under hydrostatic conditions. 9 A corresponding analytical model 23 and much more detailed finite element simulations 25 are developed to elucidate strain-induced nucleation at dislocation pile ups. The best way to study strain-induced PTs and the effect of plastic strain on thermodynamics and kinetics of PTs is to utilize combined compression and torsion loading in a rotational diamond anvil cell.…”

Section: Introductionmentioning

confidence: 99%

Strain-induced phase transformation under compression in a diamond anvil cell: Simulations of a sample and gasket

Feng

Levitas

2014

Journal of Applied Physics

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Combined high pressure phase transformations (PTs) and plastic flow in a sample within a gasket compressed in diamond anvil cell (DAC) are studied for the first time using finite element method. The key point is that phase transformations are modelled as strain-induced, which involves a completely different kinetic description than for traditional pressure-induced PTs. The model takes into account, contact sliding with Coulomb and plastic friction at the boundaries between the sample, gasket, and anvil. A comprehensive computational study of the effects of the kinetic parameter, ratio of the yield strengths of high and lowpressure phases and the gasket, sample radius, and initial thickness on the PTs and plastic flow is performed. A new sliding mechanism at the contact line between the sample, gasket, and anvil called extrusion-based pseudoslip is revealed, which plays an important part in producing high pressure. Strain-controlled kinetics explains why experimentally determined phase transformation pressure and kinetics (concentration of high pressure phase vs. pressure) differ for different geometries and properties of the gasket and the sample: they provide different plastic strain, which was not measured. Utilization of the gasket changes radial plastic flow toward the center of a sample, which leads to high quasi-homogeneous pressure for some geometries. For transformation to a stronger high pressure phase, plastic strain and concentration of a high-pressure phase are also quasi-homogeneous. This allowed us to suggest a method of determining strain-controlled kinetics from experimentation, which is not possible for weaker and equal-strength high-pressure phases and cases without a gasket. Some experimental phenomena are reproduced and interpreted. Developed methods and obtained results represent essential progress toward the understanding of PTs under compression in the DAC. This will allow one optimal design of experiments and conditions for synthesis of new high pressure phases. Combined high pressure phase transformations (PTs) and plastic flow in a sample within a gasket compressed in diamond anvil cell (DAC) are studied for the first time using finite element method. The key point is that phase transformations are modelled as strain-induced, which involves a completely different kinetic description than for traditional pressure-induced PTs. The model takes into account, contact sliding with Coulomb and plastic friction at the boundaries between the sample, gasket, and anvil. A comprehensive computational study of the effects of the kinetic parameter, ratio of the yield strengths of high and low-pressure phases and the gasket, sample radius, and initial thickness on the PTs and plastic flow is performed. A new sliding mechanism at the contact line between the sample, gasket, and anvil called extrusion-based pseudoslip is revealed, which plays an important part in producing high pressure. Strain-controlled kinetics explains why experimentally determined phase transformation pressure and kinetics...

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“…For instance, because of the similarities in stacking sequence, under pressure well-ordered hBN transforms to wBN, whereas r3N transforms to cBN [34]. For both cases, these transitions occur at room temperature only after application of pressures well above even the Bundy-Wentorf line (hBN --) wBN, P> 11 GPa [24,32]; rBN + cBN, P > 8 GPa [35]). Thus, as will be discussed in the following sections, synthesis of cBN films requires significant processing measures to overcome these kinetic or thermodynamic barriers.…”

Section: P/me Stdilir)mentioning

confidence: 99%

“…Because of this, the A, and E modes of rBN occur, respectively, at essentially the frequency as the A'" and E,, modes of hBN. Mode [43] 828 [42] 1367 [42] 1610 [42] 52 [43] 13661370 [42,-t3] 790 [44,35] rBN will be quite similar (subtle differences between rBN and hBN have been presented by Doll [48]). Poorly crystalline sp "-bonded BN (i.e.…”

Section: P/me Stdilir)mentioning

confidence: 99%

Review of advances in cubic boron nitride film synthesis

Mirkarimi¹,

McCarty²,

Medlin³

1997

Materials Science and Engineering: R: Reports

598

349

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Cubic boron nitride (cBN) has a number of highly desirable mechanical, thermal, electrical, and optical properties. Because of this, there has been an extensive worldwide effort to synthesize thin films of cBN. Film synthesis is difficult in that without significant levels of ion bombardment during growth, only sp2-bonded BN forms, not sp3-bonded cBN. Recently there has been considerable progress in improving the deposition techniques and cBN film quality. In addition, progress has been made in understanding how energetic deposition conditions can lead to cBN formation. However, unanswered questions remain and process improvements are still needed. In this paper we critically and comprehensively review recent developments in cBN film synthesis and characterization. First, the structures and stability of the BN phases and characterization techniques are described. Next, the key experimental parameters controlling cBN film formation and synthesis techniques are discussed. Following a review of microstructure, the proposed mechanisms of cBN formation and the observed mechanical and electrical properties of cBN films are analyzed. We conclude by highlighting the current impediments to the practical realization of cBN-film technology. 0 1997 Published by Elsevier Science S.A.

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Room-temperature transition of rhombohedral-type boron nitride under high static pressure

Cited by 44 publications

References 11 publications

High-pressure phases of group-IV, III–V, and II–VI compounds

High-pressure phases of group-IV, III–V, and II–VI compounds

Strain-induced phase transformation under compression in a diamond anvil cell: Simulations of a sample and gasket

Review of advances in cubic boron nitride film synthesis

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