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 - a state-of-the-art Cameca LEAP 5000 XR, an Imago/Cameca Local Electrode Atom Probe (LEAP) 3000X HR and an Oxford Nanoscience 3DAP made here in Oxford. At present these are the only atom probe instruments in the United Kingdom.

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, Dresden, Chalmers, Stockholm, Swansea, Cambridge and Delft, 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 - Lab manager

 

Location and hours of operation

Equipment Location

Cameca LEAP 5000 XR

Imago LEAP 3000X HR

 

Oxford Nanoscience 3DAP

Hume-Rothery Building, Room 20.14

Hume-Rothery Building, Room 20.11

 

Hume-Rothery Building, Room 20.11

Both atom probe instruments can run 24 hours a day. We operate in 3 fixed slots each day - 8am-2pm, 2pm-8pm and 8pm-8am. It is not possible to book in slots shorter than this. 

Usage is restricted to 8am-8pm for inexperienced users and visitors. After training, experienced users can run overnight. Users are restricted to 3 slots per fortnight unless sanctioned by the group leaders.

Due to the high vacuum required for analysis, all samples must be loaded into the LEAP 3000 and LEAP 5000 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
Lab Manager
 

 
paul.bagot@materials.ox.ac.uk
 
Room 20.09, Hume-Rothery Building
 

Available Equipment and Resources

Atom Probe (2)

Map


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