Skip to main content

Research Repository

Advanced Search

Dr John Proctor's Outputs (32)

All-optical method to directly measure the pressure–volume–temperature equation of state of fluids in the diamond anvil cell (2024)
Journal Article
Proctor, J. E., Robertson, C. E. A., Jones, L. J., Phillips, J., Watson, K., Dabburi, Y., & Moss, B. (2024). All-optical method to directly measure the pressure–volume–temperature equation of state of fluids in the diamond anvil cell. Physics of Fluids, 36(8), 087145. https://doi.org/10.1063/5.0220503

We have developed a new all-optical method to directly measure the pressure–volume–temperature (PVT) equation of state (EOS) of fluids and transparent solids in the diamond anvil high pressure cell by measuring the volume of the sample chamber. Our m... Read More about All-optical method to directly measure the pressure–volume–temperature equation of state of fluids in the diamond anvil cell.

Generally applicable physics-based equation of state for liquids. (2024)
Journal Article
Proctor, J. E., & Trachenko, K. (2024). Generally applicable physics-based equation of state for liquids. Reports on Progress in Physics, 87(9), Article 098001. https://doi.org/10.1088/1361-6633/ad6a80

Physics-based first-principles pressure-volume-temperature equations of state (EOS) exist for solids and gases but not for liquids due to the long-standing fundamental problems involved in liquid theory. Current EOS models that are applicable to liqu... Read More about Generally applicable physics-based equation of state for liquids..

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.

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.