Structural Phase Transition and Metallization of Nanocrystalline Rutile Investigated by High-Pressure Raman Spectroscopy and Electrical Conductivity

We investigate the structural, vibrational, and electrical transport properties of nanocrystalline rutile and its high-pressure polymorphs by Raman spectroscopy, and AC complex impedance spectroscopy in conjunction with the high-resolution transmission electron microscopy (HRTEM) up to ~25.0 GPa using the diamond anvil cell (DAC). Experimental results indicate that the structural phase transition and metallization for nanocrystalline rutile occurred with increasing pressure up to ~12.3 and ~14.5 GPa, respectively. The structural phase transition of sample at ~12.3 GPa is confirmed as a baddeleyite phase, which is verified by six new Raman characteristic peaks. The metallization of the baddeleyite phase is manifested by the temperature-dependent electrical conductivity measurements at ~14.5 GPa. However, upon decompression, the structural phase transition from the metallic baddeleyite to columbite phases at ~7.2 GPa is characterized by the inflexion point of the pressure coefficient and the pressure-dependent electrical conductivity. The recovered columbite phase is always retained to the atmospheric condition, which belongs to an irreversible phase transformation.

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Pressure-Induced Structural Phase Transition and Metallization in Ga2Se3 up to 40.2 GPa under Non-Hydrostatic and Hydrostatic Environments

Crystals ◽

10.3390/cryst11070746 ◽

2021 ◽

Vol 11 (7) ◽

pp. 746

Author(s):

Meiling Hong ◽

Lidong Dai ◽

Haiying Hu ◽

Xinyu Zhang

Keyword(s):

Phase Transition ◽

Electrical Conductivity ◽

High Pressure ◽

Phase Transformation ◽

Transport Properties ◽

Electrical Transport ◽

Structural Phase ◽

Structure Evolution ◽

Systematic Research ◽

Electrical Transport Properties

A series of investigations on the structural, vibrational, and electrical transport characterizations for Ga2Se3 were conducted up to 40.2 GPa under different hydrostatic environments by virtue of Raman scattering, electrical conductivity, high-resolution transmission electron microscopy, and atomic force microscopy. Upon compression, Ga2Se3 underwent a phase transformation from the zinc-blende to NaCl-type structure at 10.6 GPa under non-hydrostatic conditions, which was manifested by the disappearance of an A mode and the noticeable discontinuities in the pressure-dependent Raman full width at half maximum (FWHMs) and electrical conductivity. Further increasing the pressure to 18.8 GPa, the semiconductor-to-metal phase transition occurred in Ga2Se3, which was evidenced by the high-pressure variable-temperature electrical conductivity measurements. However, the higher structural transition pressure point of 13.2 GPa was detected for Ga2Se3 under hydrostatic conditions, which was possibly related to the protective influence of the pressure medium. Upon decompression, the phase transformation and metallization were found to be reversible but existed in the large pressure hysteresis effect under different hydrostatic environments. Systematic research on the high-pressure structural and electrical transport properties for Ga2Se3 would be helpful to further explore the crystal structure evolution and electrical transport properties for other A2B3-type compounds.

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High-pressure structural phase transition and metallization in Ga2S3 under non-hydrostatic and hydrostatic conditions up to 36.4 GPa

Journal of Materials Chemistry C ◽

10.1039/d0tc06004f ◽

2021 ◽

Author(s):

Linfei Yang ◽

Jianjun Jiang ◽

Lidong Dai ◽

Haiying Hu ◽

Meiling Hong ◽

...

Keyword(s):

Phase Transition ◽

Raman Spectroscopy ◽

High Pressure ◽

Structural Properties ◽

Structural Phase Transition ◽

First Principles ◽

Theoretical Calculations ◽

Structural Phase

The vibrational, electrical and structural properties of Ga2S3 were explored by Raman spectroscopy, EC measurements, HRTEM and First-principles theoretical calculations under different pressure environments up to 36.4 GPa.

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Structural Phase Transition and Electrical Transport Properties of CuInS2 Nanocrystals under High Pressure

The Journal of Physical Chemistry C ◽

10.1021/jp511684u ◽

2015 ◽

Vol 119 (6) ◽

pp. 2963-2968 ◽

Cited By ~ 13

Author(s):

Yan Li ◽

Ying Wang ◽

Ruilian Tang ◽

Xin Wang ◽

Pinwen Zhu ◽

...

Keyword(s):

Phase Transition ◽

High Pressure ◽

Transport Properties ◽

Structural Phase Transition ◽

Electrical Transport ◽

Structural Phase ◽

Electrical Transport Properties ◽

Cuins2 Nanocrystals

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Pressure-induced structural phase transition and dehydration for gypsum investigated by Raman spectroscopy and electrical conductivity

Chemical Physics Letters ◽

10.1016/j.cplett.2018.06.007 ◽

2018 ◽

Vol 706 ◽

pp. 151-157 ◽

Cited By ~ 4

Author(s):

Linfei Yang ◽

Lidong Dai ◽

Heping Li ◽

Haiying Hu ◽

Yukai Zhuang ◽

...

Keyword(s):

Phase Transition ◽

Electrical Conductivity ◽

Raman Spectroscopy ◽

Structural Phase Transition ◽

Structural Phase

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Phase Transition and Metallization of Orpiment by Raman Spectroscopy, Electrical Conductivity and Theoretical Calculation under High Pressure

Materials ◽

10.3390/ma12050784 ◽

2019 ◽

Vol 12 (5) ◽

pp. 784 ◽

Cited By ~ 3

Author(s):

Kaixiang Liu ◽

Lidong Dai ◽

Heping Li ◽

Haiying Hu ◽

Linfei Yang ◽

...

Keyword(s):

Phase Transition ◽

Electrical Conductivity ◽

Raman Spectroscopy ◽

High Pressure ◽

First Principles ◽

Theoretical Calculations ◽

Structural Phase ◽

Theoretical Research ◽

Continuous Change ◽

Transmission Electron

The structural, vibrational, and electronic characteristics in orpiment were performed in the diamond anvil cell (DAC), combined with a series of experimental and theoretical research, including Raman spectroscopy, impedance spectroscopy, atomic force microscopy (AFM), high-resolution transmission electron microscopy (HRTEM), and first-principles theoretical calculations. The isostructural phase transition at ~25.0 GPa was manifested as noticeable changes in the compressibility, bond lengths, and slope of the conductivity, as well as in a continuous change in the pressure dependence of the unit cell volume. Furthermore, a pressure-induced metallization occurred at ~42.0 GPa, accompanied by reversible electrical conductivity. We also determined the metallicity of orpiment at 45.0 GPa by first-principles theoretical calculations, and the results were in good agreement with the results of the temperature-dependent conductivity measurements. The HRTEM and AFM images of the recovered sample confirmed that orpiment remains in the crystalline phase with an intact layered structure and available crystal-shaped clusters. These high-pressure behaviors of orpiment present some crucial information on the structural phase transition, metallization, amorphization and superconductivity for the A2B3-type of engineering materials at high pressure.

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