Structural Phase Transitions of Ga2Se3 and GaSe under High Pressure

Takumi, Masaharu; Hirata, Akiko; Ueda, Toshikazu; Koshio, Y.; Nishimura, Hideki; Nagata, K.

doi:10.1002/1521-3951(200101)223:2<423::aid-pssb423>3.0.co;2-5

Cited by 16 publications

(17 citation statements)

References 7 publications

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“…Figure 2 shows the evolution of the intralayer first neighbour Se−In distance, as obtained from XAS experiments under pressure [9]. This distance follows a monotonous compression up to 7.1 GPa, that can be accounted for by a Murnaghan-type equation of state: Se-In Distance (Å) P (GPa) 13] it is possible to deduce the bulk modulus corresponding to the "a" parameter of the hexagonal cell, that turns out to be 44 GPa for InSe [7,14] and (61 ± 4) GPa for GaSe [15], with B′ 0 fixed to 5. It is then clear that the In−Se (Ga −Se) bond-length and the a-axis do not shrink at the same rate.…”

Section: Experimental and Calculation Methodsmentioning

confidence: 99%

Specific features of the electronic structure of III–VI layered semiconductors: recent results on structural and optical measurements under pressure and electronic structure calculations

Segura

Manjón

Errandonea

et al. 2003

Physica Status Solidi (b)

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In this paper we review some recent results on the electronic structure of III − VI layered semiconductors and its dependence under pressure, stressing the specific features that differentiate their behaviour from that of tetrahedrally coordinated semiconductors. We will focus on several unexpected results that have led to changes in the image that was currently accepted a few years ago. Intralayer bond angles change under pressure and the layer "thickness" remains virtually constant or increases. As a consequence, models based in intra-and inter-layer deformation potentials fail in explaining the low pressure nonlinearity of the band gap. Numerical-atomic-orbital/density-functional-theory electronic structure calculations allow for an interpretation of the evolution of the absorption edge under pressure. In particular, they show how the structure of the non-degenerated valence band maximum in InSe becomes more complex under pressure leading to a non-conventional direct-to-indirect crossover. The valence band maximum in InSe above 4 GPa exhibits a quite singular feature: a "ring-shaped" constant energy surface and, consequently, a density of states depending on energy as in 2D electronic systems.

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Section: Experimental and Calculation Methodsmentioning

confidence: 99%

Specific features of the electronic structure of III–VI layered semiconductors: recent results on structural and optical measurements under pressure and electronic structure calculations

Segura

Manjón

Errandonea

et al. 2003

Physica Status Solidi (b)

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“…According to the literature data, phase transitions in the 10-30 GPa pressure range are rather typical for A III B VI layered compounds [1,3,36,[39][40][41]. Nevertheless, the crystal structures of the new high-pressure A III B VI phases have not been experimentally refined so far.…”

Section: B the New High-pressure Phase Of Bsmentioning

confidence: 99%

Boron monosulfide: Equation of state and pressure-induced phase transition

Cherednichenko¹,

Kruglov

Oganov

et al. 2018

Journal of Applied Physics

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Quasi-hydrostatic compression of rhombohedral boron monosulfide (r-BS) has been studied up to 50 GPa at room temperature using diamond-anvil cells and angle-dispersive synchrotron X-ray diffraction. A fit of the experimental P-V data to the Vinet equation of state yields bulk modulus B0 of 42.2(1.4) GPa and its first pressure derivative B0′ of 7.6(2) that are in excellent agreement with our ab initio calculations. Formation of a new high-pressure phase of boron monosulfide (hp-BS) has been observed above 35 GPa. According to ab initio evolutionary crystal structure predictions combined with Rietveld refinement of high-pressure X-ray diffraction data, the structure of hp-BS has trigonal symmetry and belongs to the space group P-3m1. As it follows from electron density of states calculations, the phase transformation is accompanied by an insulator-metal transition.

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“…The combined analysis of XRD and XAS results in DAC for other III-VI layered compounds (GaS, GaSe. GaTe) [32][33][34][35][36] showed that this behavior can result in an unexpected effect: the thickness of the layer can actually increase under pressure, as shown in Figure 3b [37]. This behavior is very relevant to the discussion of the reliability of deformation potential models that were proposed to give quantitative account of the extremely non-linear pressure dependence of the bandgap in III-VI semiconductors, as we will discuss in Section 3.…”

Section: Crystal Structure Eos and Pressure-temperature Phase Diagrmentioning

confidence: 80%

“…These authors reported complex behavior including (i) a nonlinear pressure dependence of the direct bangap, exhibiting a low-pressure interval with negative pressure coefficient and then increasing with pressure after a minimum, as shown in Figure 5b; (ii) a large negative pressure coefficient for the indirect gap of GaS; and (iii) a progressive widening and disappearing of the exciton peak, as shown in Figure 5a. Concerning ε-GaSe, Panfilov et al [50] suggested that nonlinear behavior was the result of a phase transition to a different polytype occurring at 0.6 GPa, a hypothesis that was not supported by later XRD experiments [32,34]. badgap of 2 eV at RT [46].…”

Section: Optical Measurements and Ab-initio Band Structure Calculationsmentioning

confidence: 98%

Layered Indium Selenide under High Pressure: A Review

Segura

2018

Crystals

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This paper intends a short review of the research work done on the structural and electronic properties of layered Indium Selenide (InSe) and related III-VI semiconductors under high pressure conditions. The paper will mainly focus on the crucial role played by high pressure experimental and theoretical tools to investigate the electronic structure of InSe. This objective involves a previous revision of results on the pressure dependence of the InSe crystal structure and related topics such as the equation of state and the pressure-temperature crystal phase diagram. The main part of the paper will be devoted to reviewing the literature on the optical properties of InSe under high pressure, especially the absorption experiments that led to the identification of the main optical transitions, and their assignment to specific features of the electronic structure, with the help of modern first-principles band structure calculations. In connection with these achievements we will also review relevant results on the lattice dynamical, dielectric, and transport properties of InSe, as they provided very useful supplementary information on the electronic structure of the material.

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Structural Phase Transitions of Ga2Se3 and GaSe under High Pressure

Cited by 16 publications

References 7 publications

Specific features of the electronic structure of III–VI layered semiconductors: recent results on structural and optical measurements under pressure and electronic structure calculations

Specific features of the electronic structure of III–VI layered semiconductors: recent results on structural and optical measurements under pressure and electronic structure calculations

Boron monosulfide: Equation of state and pressure-induced phase transition

Layered Indium Selenide under High Pressure: A Review

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