Sample Preparation Facilities
Research Highlights
Hydrous silicate melts and the deep mantle H2O cycle
In situ observation of nanolite growth in volcanic melt: A driving force for explosive eruptions
The fate of carbonate in oceanic crust subducted into earth’s lower mantle
Structural Ordering in Liquid Gallium under Extreme Conditions
Slab melting as a barrier to deep carbon subduction
Generation of porphyry copper deposits by gas–brine reaction in volcanic arcs
Frequency and magnitude of volcanic eruptions controlled by magma injection and buoyancy
Linking Petrology and Seismology at an Active Volcano
Petrology Group members involved in €3.5m project to study processes behind volcanic unrest
Deep Mantle Cycling of Oceanic Crust: Evidence from Diamonds and their Mineral Inclusions
Petrology Group member Jon Blundy wins Royal Society Wolfson Merit Award
Primary carbonatite melt from deeply subducted oceanic crust
Petrology Group member Jon Blundy elected to Fellow of the Royal Society
The Petrology Group has a range of equipment and facilities for the preparation of samples and assemblies for high pressure experiments as well as for the preparation of run products for analysis.
Fab-Lab
The fab-lab contains the newest addition to the Petrology Group’s sample preparation facilities: an Oxford Lasers A-Series Laser Micromachining System equipped with a pulsed 1064 nm Neodymium-doped yttrium orthovanadate (Nd:YVO4) solid state laser, frequency doubled to 532 nm (Innolas NANIO 521-10-V). The nominal power output is 11.4 W at 40 kHz, with a pulse width of < 30 ns and a pulse-to-pulse stability of < 1%. Precision of the x-y stage is 1 μm, and the focused spot size is ∼3 μm. Pulse energy is 250 μJ at 40 kHz, giving a peak power of > 8.3 kW. The device contains a post-processor capable of converting CAD drawings into executable G-code for the fabrication of complex parts. This device was originally installed to manufacture micron-scale parts for diamond anvil cell assemblies, but it capable of much more, including the sectioning of run products and the extraction of mineral grains from meteorite samples and inclusions from diamonds.
The fab-lab also contains a Quorum Q150TS magnetron sputter coater. Originally designed to coat samples for microbeam analysis, it is also capable of depositing multi-micron layers of any electrically conductive material, including metals and alloys. We currently use it to ‘print’ diffusion couples and manufacture encapsulated samples for diamond anvil cell experiments. Combined with the milling machine, this equipment gives us the potential to 3-D print our experimental assemblies.
The Fab-Lab
School of Earth Sciences Polishing Lab
The Petrology Group has access to the School’s well equipped and newly refurbished polishing lab. The lab contains two Buehler auto-polishers and an auto-grinder, as well as manual polishing and grinding equipment, microscopes, a vacuum impregnation apparatus and a Buehler Isomet 1000 low-speed saw for sample sectioning. The School also has access to two diamond wire saws for precise sectioning and wafering of very small samples.
In 2021 we commissioned a new Technoorg Linda SEMPrep2™ ion polishing mill, which uses a beam of Ar+ ions to polish samples to unprecedented smoothness to optimise electron microbeam analysis.
In 2022, a new Buehler PetroThin thin-sectioning machine was also added to the polishing facility for use in teaching and research.
The polishing lab with its automatic polishing and grinding equipment
Buehler Isomet 1000 low speed saw (left); new Technoorg Linda SEMPrep2 Ion mill (right)
Buehler PetroThin thin-sectioning machine
Sample preparation labs
As well as the specialised equipment, the Petrology Group labs have two general purpose sample preparation spaces which contain microscopes, a PUK welder for closing precious-metal capsules, balances for precise weighing of starting materials, drying ovens and an array of hand tools.
Sample preparation labs
Diamond Polishing Wheel
To expose the mineral inclusions hosted by natural diamonds, we meticulously polish diamonds using a jeweller's polishing wheel.
The diamond polishing wheel
School of Earth Sciences rock crushing lab
The Petrology Group also has access to the School’s rock crushing lab, which contains a Retsch jaw-crusher, a hydraulic rock splitter and a Retsch PM100 planetary ball mill.