Oxford Materials Access to Atom Probe

Overview of Services

The Atom Probe group at Oxford is a leading research group for state-of-the-art microstructure analysis using Atom Probe Tomography and Field Ion Microscopy. We have three atom probe instruments at Oxford - two state-of-the-art Cameca LEAP 5000 XR systems, one of which is dedicated to examine nuclear materials, and a LEAP 5000 XS. All are UV-laser pulsed systems, complete with docking stations for cryo transfer, offering optimised mass resolution (XR) or detection efficiency (XS), dependent on user's needs.

Atom Probe Tomography is a powerful microstructural technique using position-sensitive time of flight mass spectrometry. A sharp needle of the desired material is produced using either electropolishing or focused ion beam (FIB). This needle is loaded into the atom probe and pumped to better than 3x10-11 Torr and cryogenically cooled to 20-70K. A high voltage is applied between the specimen tip and a local electrode. Then a pulse of either higher voltage or a laser beam is applied, enough to field evaporate 1 atom at a time into the detector. The time of flight between the pulse and the atom hitting the detector gives the mass/charge ratio and hence elemental species of the evaporated atom, and the position on the detector gives spatial information about the position of the atom within the needle. Over hours of analysis time and millions of evaporated atoms, a 3-dimensional atom-by-atom image of the chemical composition of the specimen can be reconstructed. 

The Oxford Atom Probe Group has two academic and five postdoctoral staff, as well as around 15 DPhil and Part II students. We analyse a wide variety of materials both on internal projects and in collaboration with other UK academic instititutions and industry. Our partners include the Universities of Manchester, Bristol, Imperial College, Harvard, Chalmers, Stockholm, Swansea, Cambridge, and industrial partners including Rolls Royce, National Nuclear Laboratory, AWE and Westinghouse. We study a wide range of materials including steel and tungsten alloys for fusion and fission power, steel, nickel, cobalt and titanium alloys for aeronautical and automotive applications, silicon and III-V semiconductors for computing and solar applications, zirconium and uranium alloys for fission fuel rods, catalytic nanoparticles and many others.

Leadership

Professor Michael Moody - Head of Group

Dr Paul Bagot - Senior Atom Probe Scientist/Facility manager

Dr James Douglas - Atom Probe Scientist (overseeing NNUF Nuclear Atom Probe)

 

Location and hours of operation

Equipment Location

Cameca LEAP 5000 XR

Cameca LEAP 5000 XS

Cameca LEAP 5000 XR - Nuclear Materials

 

Hume-Rothery Building, Room 20.14

Hume-Rothery Building, Room 20.11

Hume-Rothery Building, Room 00.16

 

All atom probe instruments can run 24 hours a day, usually with day/night separation into slots.

Usage is restricted to normal building working hours (9am-6pm, Mon-Fri) for inexperienced users and visitors. After training, experienced users can run overnight. Users are restricted to 2 bookings in advance on any one machine, unless sanctioned by facility staff.

Due to the high vacuum required for analysis, all samples must be loaded into the atom probes the day before operation and require at least 6 hours of pumping in the loadlock before transfer to the buffer, after which the sample should be in the buffer at least 1 hour before loading into the analysis chamber. Any user found loading their sample the same day as their slot and running it without this pumping time will have their access to the machine revoked.

 

Links and Resources

  1. Atom Probe Group Website
  2. Members of the Atom Probe Group
  3. Research
  4. LEAP handbook

Contacts

Name Role Phone Email Location
Dr Paul Bagot
Senior Atom Probe Scientist
 

 
paul.bagot@materials.ox.ac.uk
 
Room 20.09, Hume-Rothery Building
 
Dr James Douglas
Atom Probe Scientist
 

 
james.douglas@materials.ox.ac.uk
 
Room 20.10, Hume-Rothery Building
 

Available Equipment and Resources

Equipment

Name Price

Map


Department of Materials, University of Oxford Department of Materials Parks Rd Oxford OX1 3PH