High pressure photoluminescence of bismuth-doped yttria-alumina-silica glass (2022)
Journal Article
Hughes, M., McMaster, R., Proctor, J., Hewak, D., Suzuki, T., & Oshidi, Y. (2022). High pressure photoluminescence of bismuth-doped yttria-alumina-silica glass. High Pressure Research, https://doi.org/10.1080/08957959.2022.2044031

We report the effects of high pressure, up to 10.45 GPa, on the photoluminescence of Bi-doped yttria-alumina-silica (Bi:YAlSi) glass under 532 nm excitation. We identify three emission bands attributed to Bi3+, Bi+ and the controversial NIR emitting... Read More about High pressure photoluminescence of bismuth-doped yttria-alumina-silica glass.

Structural markers of the Frenkel line in the proximity of Widom lines (2021)
Journal Article
Pruteanu, C., Proctor, J., Alderman, O., & Loveday, J. (2021). Structural markers of the Frenkel line in the proximity of Widom lines. Journal of Physical Chemistry B, 125(31), 8902-8906. https://doi.org/10.1021/acs.jpcb.1c04690

We have performed a neutron scattering experiment on supercritical uid nitrogen at 160 K (1.27 TC) over a wide pressure range (7.8 MPa / 0.260 g/ml to 125 MPa / 0.805 g/ml). This has enabled us to study the process by which nitrogen changes from... Read More about Structural markers of the Frenkel line in the proximity of Widom lines.

Modeling of liquid internal energy and heat capacity over a wide pressure–temperature range from first principles (2020)
Journal Article
Proctor, J. (2020). Modeling of liquid internal energy and heat capacity over a wide pressure–temperature range from first principles. Physics of Fluids, 32, 107105. https://doi.org/10.1063/5.0025871

Recently, there have been significant theoretical advances in our understanding of liquids and dense supercritical fluids based on their ability to support high frequency transverse (shear) waves. Here, we have constructed a new computer model using... Read More about Modeling of liquid internal energy and heat capacity over a wide pressure–temperature range from first principles.

The liquid and supercritical fluid states of matter (2020)
Book
Proctor, J. (2020). The liquid and supercritical fluid states of matter. CRC Press (Taylor and Francis). https://doi.org/10.1201/9780429491443

This book addresses graduate students and researchers wishing to better understand the liquid and supercritical fluid states of matter, presenting a single cohesive treatment of the liquid and supercritical fluid states using the gas-like and solid-l... Read More about The liquid and supercritical fluid states of matter.

Experimental and theoretical confirmation of an orthorhombic phase transition in niobium at high pressure and temperature (2020)
Journal Article
Errandonea, D., Burakovsky, L., Preston, D., MacLeod, S., Santamaría-Perez, D., Chen, S., …Mezouar, M. (2020). Experimental and theoretical confirmation of an orthorhombic phase transition in niobium at high pressure and temperature. communications materials, 1, 60. https://doi.org/10.1038/s43246-020-00058-2

Compared to other body-centered cubic (bcc) transition metals, Nb has been the subject of fewer compression studies and there are still aspects of its phase diagram which are unclear. Here, we report a combined theoretical and experimental study of N... Read More about Experimental and theoretical confirmation of an orthorhombic phase transition in niobium at high pressure and temperature.

Transition from gas-like to liquid-like behavior in supercritical N2 (2019)
Journal Article
Proctor, J., Pruteanu, C., Morrison, I., Crowe, I., & Loveday, J. (2019). Transition from gas-like to liquid-like behavior in supercritical N2. Journal of Physical Chemistry Letters, 10(21), 6584-6589. https://doi.org/10.1021/acs.jpclett.9b02358

We have studied in detail the transition from gas-like to rigid liquidlike behavior in supercritical N2 at 300 K (2.4 TC). Our study combines neutron diffraction and Raman spectroscopy with ab initio molecular dynamics simulations. We observe a narr... Read More about Transition from gas-like to liquid-like behavior in supercritical N2.

Melting curve and phase diagram of vanadium under high-pressure and high-temperature conditions (2019)
Journal Article
Errandonea, D., Macleod, S., Burakovsky, L., Santamaria-Perez, D., Proctor, J., Cynn, H., & Mezouar, M. (2019). Melting curve and phase diagram of vanadium under high-pressure and high-temperature conditions. Physical Review B, 100(9), https://doi.org/10.1103/PhysRevB.100.094111

We report a combined experimental and theoretical study of the melting curve and the structural behavior of vanadium under extreme pressure and temperature. We performed powder x-ray diffraction experiments up to 120 GPa and 4000 K, determining th... Read More about Melting curve and phase diagram of vanadium under high-pressure and high-temperature conditions.

Viewpoint : graphene is thin, but not infinitely so (2019)
Journal Article
Proctor, J. (2019). Viewpoint : graphene is thin, but not infinitely so. Physics - Spotlighting Exceptional Research, 12, 104-104. https://doi.org/10.1103/Physics.12.104

Atomically thin graphene is considered a prototypical 2D material, but high-pressure experiments now reveal the 3D nature of its mechanical properties.

The effect of pressure on hydrogen solubility in Zircaloy-4 (2019)
Journal Article
Weekes, H., Dye, D., Proctor, J., Smith, D., Simionescu, C., Prior, T., & Wenman, M. (2019). The effect of pressure on hydrogen solubility in Zircaloy-4. Journal of Nuclear Materials, 524, 256-262. https://doi.org/10.1016/j.jnucmat.2019.07.012

The effect of pressure on the room temperature solubility of hydrogen in Zircaloy-4 was examined using synchrotron X-ray diffraction on small ground flake samples in a diamond anvil cell at pressures up to 20.9 GPa. Different combinations of hydrogen... Read More about The effect of pressure on hydrogen solubility in Zircaloy-4.

Observation of liquid–liquid phase transitions in ethane at 300 K (2018)
Journal Article
Proctor, J., Bailey, M., Morrison, I., Hakeem, M., & Crowe, I. (2018). Observation of liquid–liquid phase transitions in ethane at 300 K. Journal of Physical Chemistry B, 122(44), 10172-10178. https://doi.org/10.1021/acs.jpcb.8b07982

We have conducted Raman spectroscopy experiments on liquid ethane (C2H6) at 300 K, obtaining a large amount of data at very high resolution. This has enabled the observation of Raman peaks expected but not previously observed in liquid ethane and... Read More about Observation of liquid–liquid phase transitions in ethane at 300 K.

Electric discharge machine for preparation of diamond anvil cell sample chambers (2018)
Journal Article
Proctor, J., & Massey, D. (2018). Electric discharge machine for preparation of diamond anvil cell sample chambers. Review of Scientific Instruments, 89(2018), #105109. https://doi.org/10.1063/1.5050500

We have designed and constructed a novel electric discharge machine designed primarily for the preparation of sample chambers in rhenium and stainless steel gaskets for diamond anvil cell experiments. Our design combines automatic stage movement with... Read More about Electric discharge machine for preparation of diamond anvil cell sample chambers.

High pressure Raman, optical absorption, and resistivity study of SrCrO4 (2018)
Journal Article
Hakeem, M., Jackson, D., Hamlin, J., Errandonea, D., Proctor, J., & Bettinelli, M. (2018). High pressure Raman, optical absorption, and resistivity study of SrCrO4. Inorganic Chemistry, 57(13), 7550-7557. https://doi.org/10.1021/acs.inorgchem.8b00268

We studied the electronic and vibrational properties of monazite-type SrCrO4 under compression. The study extended the pressure range of previous studies from 26 to 58 GPa. The existence of two previously reported phase transitions was confirmed at 9... Read More about High pressure Raman, optical absorption, and resistivity study of SrCrO4.

Dynamics, thermodynamics and structure of liquids and supercritical fluids : crossover at the Frenkel line (2018)
Journal Article
Fomin, Y., Ryzhov, V., Tsiok, E., Proctor, J., Prescher, C., Prakapenka, V., …Brazhkin, V. (2018). Dynamics, thermodynamics and structure of liquids and supercritical fluids : crossover at the Frenkel line. Journal of Physics: Condensed Matter, 30(13), #134003. https://doi.org/10.1088/1361-648X/aaaf39

We review recent work aimed at understanding dynamical and thermodynamic properties of liquids and supercritical fluids. The focus of our discussion is on solid-like transverse collective modes, whose evolution in the supercritical fluids enables one... Read More about Dynamics, thermodynamics and structure of liquids and supercritical fluids : crossover at the Frenkel line.

Crossover between liquid-like and gas-like behaviour in CH4 at 400 K (2017)
Journal Article
Smith, D., Hakeem, M., Parisiades, P., Maynard-Casely, H., Foster, D., Eden, D., …Proctor, J. (2017). Crossover between liquid-like and gas-like behaviour in CH4 at 400 K. Physical Review E, 96(5), 052113. https://doi.org/10.1103/PhysRevE.96.052113

We report experimental evidence for a crossover between a liquid-like state and a gas-like state in fluid methane (CH4). This crossover is observed in all of our experiments, up to 397 K temperature; 2.1 times the critical temperature of methane. The... Read More about Crossover between liquid-like and gas-like behaviour in CH4 at 400 K.

Determining molecular orientation via single molecule SERS in a plasmonic nano-gap (2017)
Journal Article
Marshall, A., Stokes, J., Viscomi, F., Proctor, J., Gierschner, J., Bouillard, J., & Adawi, A. (2017). Determining molecular orientation via single molecule SERS in a plasmonic nano-gap. Nanoscale, 9(44), 17415-17421. https://doi.org/10.1039/c7nr05107g

In this work, plasmonic nano-gaps consisting of a silver nanoparticle coupled to an extended silver film have been fully optimized for single molecule Surface-Enhanced Raman Scattering (SERS) spectroscopy. The SERS signal was found to be strongly de... Read More about Determining molecular orientation via single molecule SERS in a plasmonic nano-gap.

Raman spectroscopy of methane (CH4 ) to 165 GPa : effect of structural changes on Raman spectra (2017)
Journal Article
Proctor, J., Maynard-Casely, H., Hakeem, M., & Cantiah, D. (2017). Raman spectroscopy of methane (CH4 ) to 165 GPa : effect of structural changes on Raman spectra. Journal of Raman Spectroscopy, 48(12), 1777-1782. https://doi.org/10.1002/jrs.5237

We have conducted a Raman study of methane (CH4), a major constituent of the outer planets, at pressures up to 165 GPa. We observe splitting of the principal Raman-active vibrational mode above 45 GPa and a nonlinear dependence of Raman peak position... Read More about Raman spectroscopy of methane (CH4 ) to 165 GPa : effect of structural changes on Raman spectra.

On the high-pressure phase stability and elastic properties of β-titanium alloys (2017)
Journal Article
and elastic properties of β-titanium alloys. Journal of Physics: Condensed Matter, 29(15), 155401-155401. https://doi.org/10.1088/1361-648X/aa60b6

We have studied the compressibility and stability of different β-titanium alloys at high pressure, including binary Ti–Mo, Ti–24Nb–4Zr–8Sn (Ti2448) and Ti–36Nb–2Ta–0.3O (gum metal). We observed stability of the β phase in these alloys to 40GPa, well... Read More about On the high-pressure phase stability and elastic properties of β-titanium alloys.

An introduction to graphene and carbon nanotubes (2017)
Book
Proctor, J., Melendrez Armada, D., & Vijayaraghavan, A. (2017). An introduction to graphene and carbon nanotubes. Boca Raton: CRC Press

Carbon nanotubes and graphene have been the subject of intense scientific research since their relatively recent discoveries. This book introduces the reader to the science behind these rapidly developing fields, and covers both the fundamentals and... Read More about An introduction to graphene and carbon nanotubes.

Monazite-type SrCrO4 under compression (2016)
Journal Article
Gleissner, J., Errandonea, D., Segura, A., Pellicer-Porres, J., Hakeem, M., Proctor, J., …Bettinelli, M. (2016). Monazite-type SrCrO4 under compression. Physical Review B, 94(134108), 1-13. https://doi.org/10.1103/PhysRevB.94.134108

We report a high-pressure study of monoclinic monazite-type SrCrO4 up to 26 GPa. Therein we combined x-ray diffraction, Raman, and optical-absorption measurements with ab initio calculations, to find a pressure-induced structural phase transition of... Read More about Monazite-type SrCrO4 under compression.

Theoretical and experimental study of the crystal structures, lattice vibrations, and band structures of monazite-type PbCrO4, PbSeO4, SrCrO4, and SrSeO4 (2015)
Journal Article
Errandonea, D., Munoz, A., Rodiquez-Hernandez, P., Proctor, J., Sapina, F., & Bettinelli, M. (2015). Theoretical and experimental study of the crystal structures, lattice vibrations, and band structures of monazite-type PbCrO4, PbSeO4, SrCrO4, and SrSeO4. Inorganic Chemistry, 54, 7524-7524. https://doi.org/10.1021/acs.inorgchem.5b01135

The crystal structures, lattice vibrations, and electronic band structures of PbCrO4, PbSeO4, SrCrO4, and SrSeO4 were studied by ab initio calculations, Raman spectroscopy, X-ray diffraction, and optical-absorption measurements. Calculations properl... Read More about Theoretical and experimental study of the crystal structures, lattice vibrations, and band structures of monazite-type PbCrO4, PbSeO4, SrCrO4, and SrSeO4.