Skip to main content

Research Repository

Advanced Search

Outputs (33)

Position of the Frenkel Line in supercritical nitrogen at 25°C, 75°C, 100°C and 125°C (2023)
Thesis
Al-Maiyah, A. (2023). Position of the Frenkel Line in supercritical nitrogen at 25°C, 75°C, 100°C and 125°C. (Thesis). The University of Salford

The pressure at which the Frenkel line was crossed in supercritical nitrogen was investigated at different temperatures via Raman spectroscopy, using a diamond anvil cell to control pressure and ruby or Sm:YAG as a pressure scale. The results for the... Read More about Position of the Frenkel Line in supercritical nitrogen at 25°C, 75°C, 100°C and 125°C.

A comparison of different Fourier transform procedures for analysis of diffraction data from noble gas fluids (2023)
Journal Article
Proctor, J. E., Pruteanu, C. G., Moss, B., Kuzovnikov, M. A., Ackland, G. J., Monk, C. W., & Anzellini, S. (2023). A comparison of different Fourier transform procedures for analysis of diffraction data from noble gas fluids. Journal of Applied Physics, 134(11), Article 114701. https://doi.org/10.1063/5.0161033

A comparison is made between the three principal methods for the analysis of neutron and x-ray diffraction data from noble gas fluids by direct Fourier transform. All three methods (standard Fourier transform, Lorch modification, and Soper–Barney mod... Read More about A comparison of different Fourier transform procedures for analysis of diffraction data from noble gas fluids.

Derivation of the Field Due to a Magnetic Dipole Without Use of the Vector Potential (2022)
Journal Article
Proctor, J. E., & Gould, H. T. (2023). Derivation of the Field Due to a Magnetic Dipole Without Use of the Vector Potential. Physics Teacher, 61(1), 40-42. https://doi.org/10.1119/5.0077127

The mathematical form of the magnetic field due to a current loop, and the fact that it is identical to the electric field due to an electric dipole in the far field, are fundamental to our understanding of electromagnetism. While undergraduate level... Read More about Derivation of the Field Due to a Magnetic Dipole Without Use of the Vector Potential.

Krypton and the fundamental flaw of the Lennard-Jones Potential (2022)
Journal Article
Pruteanu, C., Loveday, J., Ackland, G., & Proctor, J. (2022). Krypton and the fundamental flaw of the Lennard-Jones Potential. Journal of Physical Chemistry Letters, 13(35), 8284-8289. https://doi.org/10.1021/acs.jpclett.2c02004

We have performed a series of neutron scattering experiments on supercritical krypton. Our data and analysis allow us to characterize the Frenkel line crossover in this model monatomic fluid. The data from our measurements was analyzed using Empirica... Read More about Krypton and the fundamental flaw of the Lennard-Jones Potential.

Phase diagram of ethane above 300 K (2022)
Journal Article
Proctor, J., Spender, J., & Gould, H. (2022). Phase diagram of ethane above 300 K. Journal of Physical Chemistry C, 126(26), 10792-10799. https://doi.org/10.1021/acs.jpcc.2c00875

We have measured the melting curve of ethane from 300 to 450 K. Our results indicate that to describe all melting curve data above the triple point, it is necessary to account for a kink in the melting curve where the phase III–phase IV solid–solid t... Read More about Phase diagram of ethane above 300 K.

Characterization of the high-pressure and high-temperature phase diagram and equation of state of chromium. (2022)
Journal Article
Anzellini, S., Errandonea, D., Burakovsky, L., Proctor, J., Turnbull, R., & Beavers, C. (2022). Characterization of the high-pressure and high-temperature phase diagram and equation of state of chromium. Scientific reports, 12(1), 6727. https://doi.org/10.1038/s41598-022-10523-2

The high-pressure and high-temperature phase diagram of chromium has been investigated both experimentally (in situ), using a laser-heated diamond-anvil cell technique coupled with synchrotron powder X-ray diffraction, and theoretically, using ab ini... Read More about Characterization of the high-pressure and high-temperature phase diagram and equation of state of chromium..

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.

Mechanical properties of graphene (2021)
Journal Article
Sun, Y. W., Papageorgiou, D. G., Humphreys, C. J., Dunstan, D. J., Puech, P., Proctor, J. E., …San-Miguel, A. (2021). Mechanical properties of graphene. Applied Physics Reviews, 8(2), 021310. https://doi.org/10.1063/5.0040578

This paper reviews the mechanical properties of graphene with particular attention to what is established and what is still uncertain. It clarifies the thickness and the elastic constants, and by also considering also phonon frequencies, it argues th... Read More about Mechanical properties of graphene.

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.

Raman spectroscopy of ethane (C 2 H 6 ) to 120 GPa at 300 K (2020)
Journal Article
Read, L., Spender, J., & Proctor, J. (2020). Raman spectroscopy of ethane (C 2 H 6 ) to 120 GPa at 300 K. Journal of Raman Spectroscopy, 51(11), 2311-2317. https://doi.org/10.1002/jrs.5971

We have conducted a Raman study of solid ethane (C2H6) at pressures up to 120 GPa at 300 K. We observe changes within the ν3 and ν11 Raman‐active vibrational modes providing evidence for several previously unobserved phase transitions at room tempera... Read More about Raman spectroscopy of ethane (C 2 H 6 ) to 120 GPa at 300 K.

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.

Influence of synthesis conditions on the structure of nickel nanoparticles and their reactivity in selective asymmetric hydrogenation (2019)
Journal Article
Arrigo, R., Gallarati, S., Schuster, M., Seymour, J., Gianolio, D., da Silva, I., …Held, G. (2020). Influence of synthesis conditions on the structure of nickel nanoparticles and their reactivity in selective asymmetric hydrogenation. ChemCatChem, 12(5), 1491-1503. https://doi.org/10.1002/cctc.201901955

Unsupported and SiO2-supported Ni nanoparticles (NPs), were synthesised via hot-injection colloidal route using oleylamine (OAm) and trioctylphosphine (TOP) as reducing and protective agents, respectively. By adopting a multi-length scale structural... Read More about Influence of synthesis conditions on the structure of nickel nanoparticles and their reactivity in selective asymmetric hydrogenation.

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.

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.

Liquid mysteries (2018)
Journal Article
Proctor, J. (2018). Liquid mysteries. Physics world, 31(5), https://doi.org/10.1088/2058-7058/31/5/37

It's easy to assume there's nothing new to learn about liquids. John Proctor explains just how weird liquids can be at high pressures and why this work could shed light on planetary interiors.

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.

Hydrogenation of graphene by reaction at high pressure and high temperature (2015)
Journal Article
Smith, D., Howie, R., Crowe, I., Simionescu, C., Muryn, C., Vishnyakov, V., …Proctor, J. (2015). Hydrogenation of graphene by reaction at high pressure and high temperature. ACS nano, 9(8), 8279-8283. https://doi.org/10.1021/acsnano.5b02712

The chemical reaction between hydrogen and purely sp2-bonded graphene to form graphene's purely sp3-bonded analogue, graphane, potentially allows the synthesis of a much wider variety of novel two-dimensional materials by opening a pathway to the app... Read More about Hydrogenation of graphene by reaction at high pressure and high temperature.

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.

Stabilization of boron carbide via silicon doping (2014)
Journal Article
Proctor, J., Bhakhri, V., Hao, R., Prior, T., Scheler, T., Gregoryanz, E., …Giuliani, F. (2015). Stabilization of boron carbide via silicon doping. Journal of Physics: Condensed Matter, 27(1), 015401. https://doi.org/10.1088/0953-8984/27/1/015401

Boron carbide is one of the lightest and hardest ceramics, but its applications are limited by its poor stability against a partial phase separation into separate boron and carbon. Phase separation is observed under high non-hydrostatic stress (both... Read More about Stabilization of boron carbide via silicon doping.

Equation of state and high-pressure/high-temperature phase diagram of magnesium (2014)
Journal Article
Stinton, G., Macleod, S., Cynn, H., Errandonea, D., Evans, W., Proctor, J., …McMahon, M. (2014). Equation of state and high-pressure/high-temperature phase diagram of magnesium. Physical review B: Condensed matter and materials physics, 90(13), 134105-134105. https://doi.org/10.1103/PhysRevB.90.134105

The phase diagram of magnesium has been investigated to 211 GPa at 300 K, and to 105 GPa at 4500 K, by using a combination of x-ray diffraction and resistive and laser heating. The ambient pressure hcp structure is found to start transforming to the... Read More about Equation of state and high-pressure/high-temperature phase diagram of magnesium.