PhD Opportunity: Crystal growth and neutron scattering of functional materials

About the Project

PhD Opportunity: Crystal growth and neutron scattering of functional materials

(UCL Crystal Growth Laboratory @ Rutherford Appleton Laboratory, Harwell Campus)

Modern technologies increasingly rely on “functional materials” whose performance is set by how electrons, ions, and heat move through a crystal lattice. Transparent conducting oxides enable displays and photovoltaics; solid-state battery materials underpin safer, higher-energy devices; thermoelectrics offer routes to convert waste heat into useful power. In all of these systems, the key physics is microscopic: defects, disorder, stoichiometry, and lattice dynamics control transport, stability, and device-relevant performance. This PhD is built around a simple principle: to understand (and ultimately design) functional materials, you need definitive samples and definitive probes. High-quality single crystals eliminate grain-boundary effects, enable anisotropic measurements, and unlock neutron-scattering experiments that cannot be performed meaningfully on powders or strained thin films. Neutrons are uniquely powerful for locating light elements (e.g., O, Li, H) and for measuring atomic motion—exactly the information needed to connect structure and dynamics to function.

The project is based at the UCL Crystal Growth Laboratory on the Harwell Science and Innovation Campus in Oxfordshire, one of Europe’s leading centres for large-scale science. Harwell brings together national laboratories, universities, and high-technology companies in a uniquely collaborative environment focused on materials, energy, and advanced instrumentation. The laboratory sits alongside the ISIS Neutron and Muon Source, the UK’s national facility for neutron scattering. ISIS provides world-class instruments for diffraction, total scattering, inelastic and quasielastic neutron spectroscopy, and related techniques that probe structure and dynamics across multiple length and time scales. Being embedded directly within this ecosystem enables a seamless connection between crystal growth and advanced characterisation: samples grown in-house can be rapidly evaluated using state-of-the-art neutron instrumentation, often in close discussion with instrument scientists. The campus also hosts complementary facilities in electron microscopy, X-ray science, materials chemistry, and engineering. For a doctoral researcher, this environment offers both intellectual breadth and technical depth - exposure to fundamental condensed matter physics, real materials challenges, and national-scale experimental infrastructure - all within a concentrated and highly interactive scientific community.

Transformational capability: new high-pressure laser furnace

A central feature of this PhD is access to a newly commissioned laser-heated, high-gas-pressure floating-zone furnace at FACET (Harwell Campus, www.facet-crystal.co.uk). Operating at pressures up to 300 bar, the laser furnace stabilises the molten zone at very high temperatures and suppresses volatile constituents under pressure. This capability is transformative: it enables single-crystal growth of oxide and chalcogenide materials that are otherwise extremely challenging (or impossible) to produce as large, high-purity crystals.

Research themes (the specific PhD topic will be defined with the successful candidate)

The project is intentionally broad, allowing you to shape the scientific direction around your interests while staying anchored to crystal growth + neutron scattering. Example themes include:

• Transparent conducting oxides (TCOs)
  The new laser furnace can routinely grow materials like In2O3 and ZnO, which when doped conducy electicity whilst simultaneously being transparent to optical radiation. Discovery and optimisation of earth-abundant TCOs, and quantitative understanding of how dopants and defects set the transparency–conductivity limits. Our work includes the experimental realisation of Ga-doped ZnSb2O6 as an earth-abundant transparent conducting oxide.
• Solid-state battery materials
  Growth of single crystals of fast-ion conductors (e.g., garnets, argyrodites, thiophosphates) and neutron-scattering studies that link local structure and lattice dynamics to ionic transport (including correlated disorder, diffusion pathways, and vibrational modes).
• Thermoelectrics and related energy materials
  Crystal-growth-led control of disorder and phonons to tune thermal transport and electronic performance in complex functional compounds.

What you will do

The exact balance depends on the chosen material family, but typical activities include:

• Single-crystal growth using high-temperature methods, including laser-heated floating-zone growth under high pressure (control of stoichiometry, defect chemistry, and volatility)
• Structural and chemical characterisation (single-crystal X-ray diffraction; complementary composition / surface tools where appropriate)
• Neutron scattering at ISIS to probe average structure, local order, and—where relevant—dynamics (diffraction, diffuse scattering / ΔPDF, inelastic and quasi-elastic neutron scattering)
• Property measurements matched to the function of the material system (e.g., electrical transport and Hall effect for TCOs; impedance spectroscopy for ionic conductors; thermal transport measurements for thermoelectrics)

You will work in a national-lab environment on Harwell Campus, Oxfordshire, with close access to world-leading scattering facilities and expertise.

Candidate profile

Applicants should have (or expect to obtain) a 1st or strong 2:1 (or international equivalent) in Physics, Materials Science, Chemistry, or a related discipline. You should enjoy hands-on laboratory research and quantitative analysis. Prior experience in crystal growth and/or scattering is welcome but not required.

Funding notes

This project currently has no allocated studentship. We welcome applications from:

• Self-funded candidates, or those with external scholarships
• China Scholarship Council (CSC) applicants (we can support CSC applications to UCL; deadline January 2027)
• UK applicants: an open call is expected in November 2026 for funded places starting October 2027

How to apply / informal enquiries

Serious prospective applicants are encouraged to visit the laboratories at Harwell for a guided tour and discussion of potential project directions.

Please email Prof Robin Perry with a CV (and, if available, transcripts and a short statement of interests): robin.perry@ucl.ac.uk

Applications are considered on a rolling basis.