I am a scientist working across the chemistry-physics boundary. My focus is on structure-property relationships in advanced functional materials and quantum phases (with the former including ferroelectrics and multiferroics and the latter materials whose properties are driven by quintessentially quantum phenomena such as quantum spin liquids and unconventional superconductors). The core experimental tools I employ include solid state sample synthesis (including substitutional studies order to tune material properties), detailed characterisation measurements, physical property measurements and, last but not least, high resolution neutron diffraction.
My main interest is in structure-property relationships in transition metal oxides.
I completed my PhD at the University of St Andrews (working in both the Chemistry and Physics departments) working on a range of transition metal oxides including YMnO3 and BiFe0.7Mn0.3O3 (both multiferroics), Sr2RuO4 (superconductivity), PdCoO2 and PdCrO2 (ultra-high conductivity delafossite metals) and Dy2Ti2O7 (spin ice).
Following this I was a postdoctoral researcher at the University of Tokyo, a visiting researcher at RIKEN, Wako-shi (Japan) and at the Max Planck Institute for Solid State Research, Stuttgart (Germany). During this time I primarily focused on new quantum magnets.
Since February 2016 I have been a scientist in the ISIS Crystallography Group.
A more detailed overview of my past and current research is given below. Please feel free to contact me if you are a potential user interested in collaborating on measurements on HRPD or if any of my expertise might be helpful in planning your experiments.
High resolution neutron diffraction studies of ferroelectrics and multiferroics
Ferroelectrics and multiferroics are both useful for applications in everyday devices and of fundamental interest for the phase transitions and complex physical properties they host. I have a particular interest in studying these materials using high resolution neutron diffraction and symmetry mode analysis to elucidate the structural distortions driving these properties.
New quantum magnets
Quantum magnets provide an intriguing range of physics to explore, closely linked to structural distortions. I am interested in synthesis, high resolution structural studies and detailed physical property measurements of such materials.
"S=1/2 quantum critical spin ladders produced by orbital ordering in Ba2CuTeO6", Phys. Rev. B 95, 104428 (2017)
Structure and magnetism in iridates
I have pioneered the use of 193Ir, a previously unused isotope of iridium with improved neutron scattering characteristics compared to the natural isotopic mixture. I am now focusing on exploiting this in studies of the structure-property relationships in iridates.
"Neutron scattering length determination by means of total scattering", J. Appl. Cryst. 51, 854 (2018)
"Pressure-induced collapse of the spin-orbital Mott state in the hyperhoneycomb iridate β−Li2IrO3",
Phys. Rev. B. 99, 125127 (2019)
Strongly correlated electron systems
These are materials in which strong electron-electron interactions give rise to intriguing, and often surprising, electronic states. My interest is largely in growth of ultra-pure single crystals by the floating zone method, combined with physical property measurements at low temperatures (e.g. ac susceptibility, quantum oscillations, resistivity).
"Resistivity in the Vicinity of a van Hove Singularity:
Sr2RuO4 under Uniaxial Pressure", Phys. Rev. Letters 120, 076602 (2018)
"Strong peak in Tc of Sr2RuO4 under uniaxial pressure", Science 355, eaaf9398 (2017)
"Search for spontaneous edge currents and vortex imaging in
Sr2RuO4 mesostructures", Phys. Rev. B 89, 144504 (2014)
"Strong Increase of Tc of Sr2RuO4 under both Tensile and Compressive Strain", Science, 344, 283 (2014)
Ultra-pure delafossite metals
Metallic delafossite oxides such as PdCoO2, PdCrO2 and their relatives show incredibly high conductivities and are a playground for investigating the fundamentals of electronic transport in solids. I have investigated the Fermi surfaces and electronic properties of these materials using quantum oscillation measurements at millikelvin temperatures.
“Quantum oscillations and magnetic reconstruction in the delafossite PdCrO2”, Phys. Rev. B, 92, 014425 (2015)
"Quantum Oscillations and High Carrier Mobility in the Delafossite PdCoO2", Phys. Rev. Letters, 109, 116401 (2012)
Key expertise
I have experience in a variety of synthesis methods (e.g. solid state, floating zone, flux, hydrothermal), physical property measurements (e.g. specific heat, resistivity, impedance spectroscopy, ac susceptibility, torque magnetometry) and a wide range of neutron scattering measurements.
