Methods

I am always open to collaboration, and welcome interested parties to contact me.


MIT Lab @ Kyushu University

With my colleague Dr Dino Klotz, I manage the ‘MIT Lab @ Kyushu University’ situated in room 406 of the I2CNER/NEXT-FC building. With a fume hood, combustion furnace, drying oven, hot plates, mass balance, ball mill, and uniaxial press, we can synthesis ceramics via solid-state or nitrate routes. We also have a thermo-gravimetric analysis setup (TGA) for investigated changes in non-stoichiometry and a dilatometer for studying chemical expansion effects in ceramics.

We have several set-up for studying the electrical properties of ceramics and thin films as a function of temperature and oxygen partial pressure. Combined with impedance spectroscopy, this offers a powerful method to separate electrochemical processes with different characteristic time scales and allows the investigation of conductivity, surface exchange rates, and non-stoichiometry, electrically. Furthermore, some of the set-ups have windows for monitoring optical changes in films, which turns out to be a useful tool in investigating the non-stoichiometry and surface exchange in optically active materials. Most of the set-ups can be automated using the LabView software.

Optical setup built by Nicola Perry

Pulsed Laser Deposition (PLD)

NEXT-FC PLD

PLD is a technique to grow films of complex oxides easily and routinely (although obtaining the desired composition, orientation, and microstructure is the tricky part). A high energy laser is used to ablate a dense ceramic stoichiometric target to create a ‘plume’ which is incident on a heated (usually single-crystal) substrate. PLD provides a method to fabricate high quality oxide films and a means to control properties such as thickness, strain, crystallinity, grain size and microstructure, as well as engineer well-defined oxide interfaces for study.

I am the manager of the PLD facilities in the NEXT-FC institute at Kyushu University.


X-ray Diffraction (XRD)

XRD is arguably the most important tool for the characterisation of thin films (along with electron microscopy – see below). It involves scattering a coherent beam of X-rays off the surface region of a sample and detected as a function of scattering angle, and is relatively fast, non-destructive, and highly accurate. XRD can provide information on the thickness, orientation, crystallinity, texture, lattice parameters and strain.

I am the manager of the Rigaku Smartlab in the I2CNER institute, which is equipped with a high intensity (9 kW) source, and a Ge (220)x2 monochromator for high resolution work, and five-axis goniometer including an in-plane diffraction arm. Typical measurements include X-ray reflectivity (film thickness), 2theta/omega scans (out-of-plane orientation and lattice parameters), rocking curves (mosaic spread, texture), pole figures (in-plane orientation), 2theta-chi/phi (in-plane lattice parameters) and reciprocal space maps.

I2CNER XRD

Transmission Electron Microscopy (TEM)

HAADF-STEM image of a PCO/STO multilayer

Whereas XRD may be one of the most important tools for thin film engineering, TEM may be one of the most important tools for materials science as a whole. The information provided by TEM complements that obtained from XRD particularly well. While XRD yields information representative of a large proportion of the film volume, TEM probes a much smaller volume, but provides information at sub-atomic spatial resolution.

High energy electrons illuminate a thin cross-section of sample (typically prepared using the ‘lift-out’ method on a dual-beam focused ion beam/scanning electron microscope) producing either a greatly magnified image or electron diffraction pattern. Film morphology, microstructure, orientation relationships, and phase identification, can all be investigated at highly localised regions. Focusing the electron beam to a fine probe and rastering it across the sample (scanning transmission electron microscopy - STEM), opens up powerful new imaging techniques, as well as the ability to gain chemical information at the sub-atomic level with X-ray energy-dispersive spectrometry (XEDS – compositional information) and electron energy loss spectrometry (EELS – composition and electronic structure)./p>

I frequently use the JEOL ARM200F TEM at the High-Voltage Electron Microscopy Centre (HVEM) at Kyushu University. Equipped with a field emission gun, Cs correctors of the probe-forming and images lenses, XEDS, and EELS detector, it is a versatile and powerful instrument for high resolution and analytical TEM.


Other facilities/expertise

Also regularly use scanning electron microscopy, Raman spectroscopy, and magnetron sputtering for metal film deposition.

I also have extensive experience in ion beam analysis using low energy ion scattering (LEIS) as well as secondary ion mass spectrometry (SIMS) in conjunction with oxygen isotope tracer diffusion.