Deviatoric stress-induced quasi-reconstructive phase transition in ZnTe

Zhuang, Yukai; Wu, Lei; Gao, Bo; Cui, Zhongxun; Gou, Huiyang; Zhang, Dongzhou; Zhu, Shengcai; Hu, Qingyang

doi:10.1039/c9tc06334j

Cited by 12 publications

(13 citation statements)

References 28 publications

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“…However, unlike the previous experimental confirmation of post-perovskite structure requiring significant strain and/or large atomic displacements, such reversible transformation in LiSbO 3 needs only relatively small atomic displacements, indirectly related to Γ 1 – and Γ 2 modes. Hence, it is neither fully reconstructive nor fully displacive, which should be called displacive-/quasi-reconstructive transition. , Although the Sb:A Pnma state possesses lower enthalpy under the pressure range of 55–145 GPa, the phase transitions between these two hexagonal phases more easily occur on experiment due to the nature of displacive-/quasi-reconstructive transition. However, the Sb:A Pnma state should be directly synthesized under high temperatures and high pressures via laser heating-driven reconstructive transition.…”

Section: Resultsmentioning

confidence: 99%

Pressure-Induced High-κ Dielectric Properties and Multiple Phase Transitions between Novel Nonperovskite and Perovskite Phases in LiSbO₃: A First-Principles Study

et al. 2020

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The pressure effects on LiSbO3 have been investigated via first-principles simulation. Multiple pressure-induced reconstructive phase transitions between nonperovskite and perovskite states are revealed, i.e., undergoing Pncn-to-R3c-to-P6322-to-Sb:A Pnma-to-P63/m phase transitions with increasing pressure. New nonperovskite P6322 and P63/m states, not present on experiment, can form a reversible transformation (belonging to displacive-/quasi-reconstructive transition in nature) with the increase and decrease of pressure, involving indirect softening of two unstable phonon modes via symmetry analysis. The anomalous formation of a novel Sb:A Pnma state, instead of the Sb:B Pnma state as we commonly expected, is also revealed and explicated by the change of Li–O and Sb–O bonds as well as the limit of the typical tolerance factors. The dielectric response and anomalous larger band gap under a high pressure are also accompanied by the change of direct-to-indirect band gap. All of these findings stimulate interest in the exploration and experimental confirmation of such novel and diverse nonperovskite and perovskite structures as well as their optical applications.

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Section: Resultsmentioning

confidence: 99%

Pressure-Induced High-κ Dielectric Properties and Multiple Phase Transitions between Novel Nonperovskite and Perovskite Phases in LiSbO₃: A First-Principles Study

et al. 2020

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“…Non‐ambient studies of these systems revealed a number of phase transitions, [8, 9, 12–25] which can be partially attributed to the non‐hydrostatic conditions and stress generated beyond the hydrostatic limits of pressure‐transmitting media [26–28] . Naturally, there are numerous examples of materials with various structure types and dimensionalities that show differences in phase‐transformation pressures under hydrostatic and non‐hydrostatic conditions [29–31] . In general, shear stress is believed to reduce the nominal transition pressure due to either decrease of the height of the potential barrier or high‐pressure phase nucleation at new defects generated during plastic deformation, as discussed in a comprehensive review by Levitas [32] .…”

Section: Introductionmentioning

confidence: 99%

“…[26][27][28] Naturally,there are numerous examples of materials with variouss tructure types and dimensionalities that show differences in phase-transformation pressures under hydrostatic and non-hydrostatic conditions. [29][30][31] In general, shear stress is believed to reduce the nominal transition pressure due to either decrease of the heighto ft he potentialb arrier or high-pressure phase nucleation at new defects generated during plastic deformation,a sd iscussed in ac omprehensive review by Levitas. [32] In this study,w edecided to distinguish a group of cage compounds,f orming molecular crystals with high (cubic or hexagonal) symmetry.R elevant literature data are summarized in Table S1.…”

Section: Introductionmentioning

confidence: 99%

Crystal Structure and Non‐Hydrostatic Stress‐Induced Phase Transition of Urotropine Under High Pressure

Guńka

Olejniczak

Fanetti

et al. 2020

Chemistry A European J

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High-pressure behavior of hexamthyleneteramine (urotropine) was studied in situ using angledispersive single-crystal synchrotron X-ray diffraction (XRD) and Fourier transform infrared absorption (FTIR) spectroscopy. Experiments were conducted in various pressure transmitting media (helium and neon for XRD, nitrogen and KBr for FTIR experiments) to study the effect of deviatoric stress on phase transformations. Contrary to As4O6 arsenolite, a material of similar cage-like molecular structure, no pressure-induced helium penetration into the crystal structure was observed. Instead, two pressure-induced structural changes are observed. The first one is suggested by the following occurrences: (i) gradual quenching of the magnitudes of atomic displacement parameters, (ii) diminishing libration contribution to the experimental C−N bond length, (iii) discontinuity in calculated IR-active vibrational modes and (iv) asymptotically vanishing discrepancy between the experimental and DFT-calculated unit cell volume. All these features reach a plateau at ~4 GPa and can be attributed to a damping of molecular librations and atomic thermal motion, pointing to the existence of a second-order isostructural phase transition. The second transformation, with an onset at ~12.5 GPa is a first-order phase transition to a tetragonal structure, characterized by sluggish kinetics and considerable hysteresis upon decompression. However, it occurs only in non-hydrostatic conditions, induced by a deviatoric stress in the sample. This behavior finds analogies in similar cubic crystals built of highly symmetric cage-like molecules and may be considered a common feature of such systems. Last but not least, it is worth noting successful Hirshfeld atom refinements, carried out for the incomplete high-pressure diffraction data up to 14 GPa, yielded more realistic C−H bond lengths than the independent atom model.

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“…[26][27][28] Naturally, there are numerous examples of materials with various structure types and dimensionalities that show differences in phase transformation pressures under hydrostatic and non-hydrostatic conditions. [29][30][31] In general, shear stress is believed to reduce the nominal transition pressure due to either decrease of the height of the potential barrier or highpressure phase nucleation at new defects generated during plastic deformation, as discussed in a comprehensive review by Levitas. 32 In spite of these reservations, we decided to distinguish a group of cage compounds, forming molecular crystals with high (cubic or hexagonal) symmetry.…”

Section: Introductionmentioning

confidence: 99%

Crystal structure and non-hydrostatic stress-induced phase transition of urotropine under high pressure

Guńka¹,

Olejniczak²,

Fanetti³

et al. 2020

Preprint

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High-pressure behavior of hexamthyleneteramine (urotropine) was studied in situ using angle-dispersive single-crystal synchrotron X-ray diffraction (XRD) and Fourier transform infrared absorption (FTIR) spectroscopy. Experiments were conducted in various pressure transmitting media (helium and neon for XRD, nitrogen and KBr for FTIR experiments) to study the effect of deviatoric stress on phase transformations. Contrary to As4O6 arsenolite, a material of similar cage-like molecular structure, no pressure-induced helium penetration into the crystal structure was observed. Instead, two pressure-induced structural changes are observed. The first one is suggested by the following occurrences: (i) gradual quenching of the magnitudes of atomic displacement parameters, (ii) diminishing libration contribution to the experimental C−N bond length, (iii) discontinuity in calculated IR-active vibrational modes and (iv) asymptotically vanishing discrepancy between the experimental and DFT‑calculated unit cell volume. All these features reach a plateau at ~4 GPa and can be attributed to a damping of molecular librations and atomic thermal motion, pointing to the existence of a second-order isostructural phase transition. The second transformation, with an onset at ~12.5 GPa is a first-order phase transition to a tetragonal structure, characterized by sluggish kinetics and considerable hysteresis upon decompression. However, it occurs only in non-hydrostatic conditions, induced by a deviatoric stress in the sample. This behavior finds analogies in similar cubic crystals built of highly symmetric cage-like molecules and <a>may be considered a common feature</a> of such systems. Last but not least, it is worth noting successful Hirshfeld atom refinements, carried out for the incomplete high-pressure diffraction data up to 14 GPa, yielded more realistic C−H bond lengths than the independent atom model.

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Deviatoric stress-induced quasi-reconstructive phase transition in ZnTe

Abstract: A new phase transition mechanism induced by deviatoric stress was found and named as “quasi-reconstructive” transition.

Cited by 12 publications

References 28 publications

Pressure-Induced High-κ Dielectric Properties and Multiple Phase Transitions between Novel Nonperovskite and Perovskite Phases in LiSbO₃: A First-Principles Study

Pressure-Induced High-κ Dielectric Properties and Multiple Phase Transitions between Novel Nonperovskite and Perovskite Phases in LiSbO₃: A First-Principles Study

Crystal Structure and Non‐Hydrostatic Stress‐Induced Phase Transition of Urotropine Under High Pressure

Crystal structure and non-hydrostatic stress-induced phase transition of urotropine under high pressure

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Deviatoric stress-induced quasi-reconstructive phase transition in ZnTe

Abstract: A new phase transition mechanism induced by deviatoric stress was found and named as “quasi-reconstructive” transition.

Cited by 12 publications

References 28 publications

Pressure-Induced High-κ Dielectric Properties and Multiple Phase Transitions between Novel Nonperovskite and Perovskite Phases in LiSbO3: A First-Principles Study

Pressure-Induced High-κ Dielectric Properties and Multiple Phase Transitions between Novel Nonperovskite and Perovskite Phases in LiSbO3: A First-Principles Study

Crystal Structure and Non‐Hydrostatic Stress‐Induced Phase Transition of Urotropine Under High Pressure

Crystal structure and non-hydrostatic stress-induced phase transition of urotropine under high pressure

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Pressure-Induced High-κ Dielectric Properties and Multiple Phase Transitions between Novel Nonperovskite and Perovskite Phases in LiSbO₃: A First-Principles Study

Pressure-Induced High-κ Dielectric Properties and Multiple Phase Transitions between Novel Nonperovskite and Perovskite Phases in LiSbO₃: A First-Principles Study