Atom Probe Tomography

IIT Madras has established the National Facility for Atom Probe Tomography (NFAPT) which houses a state of art atom probe tomography "Local Electrode Atom Probe (LEAP 5000 XR)" along with "Helios Dual Beam Scanning Electron Microscope with Focused Ion Beam (FIB)" for LEAP sample preparation. IIT Bombay, as a founding partner institute, has a remote terminal for the operation of the instrument and software for the analysis of the data after data acquisition.

This is the first remotely operable LEAP facility in the world. Any researcher in India can use the facility by contacting the NFAPT management. More details can be found on NFAPT | Home (iitm.ac.in)

Make and Model

Make: CAMECA

Model: LEAP 5000XR

Application

    •  Interface analysis in magnetostrictive materials.
    •  Grain boundary analysis in metals.
    •  Investigation of phase change separation processes.
    •  Atomic scale characterization of dopants.
    •  Characterization of advanced alloys.
    •  Thin film characterization.
    •  Oxide growth in metals.

Facility in-charge

Contact Email

aptlab[at] iitb[dot] ac[dot] in amitkumbhar[at] iitb[dot] ac[dot] in

Contact no.

022-21596864

Location

National Facility for Atom Probe Tomography (NFAPT)
HSB-134, Indian Institute of Technology Madras
Chennai-600036, India.

Hardware and Software for remote access and analysis located at:

Room No: 414,1st Floor
Department of SAIF/CRNTS
Indian Institute of Technology, Bombay
Powai – 400076

Technical Specifications
  •   Reflectron ion optic design
  •   Field of view up to 200 nm
  •   Voltage and Laser modes
  •   Mass resolving power 1100
  •   Specimen temperature 25K to 80K
  •   355 nm UV laser for laser mode
  •   Laser energy range from 0.001 pJ to 1000 pJ
  •   Less than 3 micro meter laser spot size
  •   Up to 500 kHz pulse rate for laser

Atom probe tomography is a unique characterization technique that facilitates three-dimensional visualization as well as in‐depth analysis of nano‐scale features at near‐atomic scale resolution (lateral resolution: 0.3-0.5 nm and depth resolution 0.1-0.3 nm), 3D information about the position of each atom in the analyzed sample and chemical sensitivity down to atomic parts per million. A sharp tip sample is prepared using Focused Ion Beam (FIB).

Prepared sample is then cooled to ~ 50K in the analysis chamber of the microscope. The tip is biased at high DC voltage (3-15 kV) and due to the sharpness of the tip, high electrostatic field can be generated. This field is sufficient to field evaporate atoms from the surface of the sample. By applying voltage pulse or laser pulse the field evaporated ions are projected on the position sensitive detector. Time (Time of flight measurement) taken by the ions to reach the detector is noted and the x, y position of the ions is detected. This allows to reconstruct the original position of the evaporated atoms in the analyzed sample.

Central facility presentation
Publications using data from this facility
  1. High Pressure Torsion Processing of Maraging Steel 250: Microstructure and Mechanical Behaviour Evolution, Kevin Jacob, K., Yadav, D., Dixit, S., Hohenwarter, A. and Jaya, B.N., 2020. Materials Science and Engineering: A, p.140665.
  2. Evolution of sub-surface microstructure under linear reciprocating wear of nanostructured bainitic steel, Kritika Singh, Sudharm Rathore, Aparna Singh, Materials Characterization (2021),Vol 180: 111407. 
  3. Oriented assembly of Ni-clusters embedded in semi-insulating NiO epitaxial films, Santosh Kumar Yadav, Bhabani Prasad Sahu and Subhabrata Dhar, J. Phys. D: Appl. Phys. 55 (2022) 035002 (7pp).
  4. Effect of dislocation network on precipitate morphology and deformation behaviour in maraging steels: Modelling and experimental validation,Kevin Jacob, Abhinav Roy, M P Gururajan, Nagamani Jaya Balila
  5. Formation of tungsten carbide by focused ion beam process: A route to high magnetic field resilient patterned superconducting nanostructures, H Chakraborti et al. Appl. Phys. Lett. 120,132601 (2022).
  6. 6.Revealing a correlation between microstructure, stoichiometry, coherency strains and mechanical behavior of bulk polycrystalline oxide-based age hardened/toughened ceramic alloys, Luv Gurnani and Amartya Mukhopadhyay, Materials Science and Engineering: A 854 (2022) 143810.
  7. Micro-mechanisms of failure in nano-structured maraging steels characterised through in situ mechanical tests, Jacob, K., Sahasrabuddhe, H., Hohenwarter, A., Dixit, S. and Jaya, B.N., 2022. Nanotechnology.
  8. An experimental study on laser ablation of Ultra-thin SiNx layer of PERC solar cells, Pinal Rana, Durga Prasad Khatri, Anil Kottantharayil, and Deepak Marla.  DOI: 10.1177/25165984221129958
  9. Understanding the effects of tetrahedral site occupancy by Zn-dopant in Li-NMC towards high voltage compositional-structural-mechanical stability via operando and 3D Atom Probe Tomography studies, A. Sharma, A. H. Pandey, M. K. Jangid, V. Srihari, H. K. Poswal, A. Mukhopadhyay, ACS Appl. Mater. Interfaces, 2023, 15, 1, 782–794.
Instructions for sample preparation/submission

Sample dimensions may vary from thin film samples to small blocks (1 cubic cm) of metallic or non-metallic materials. Porous or soft samples cannot be analyzed using APT. All information about the material including processing technique and mechanical properties should be provided with the sample. It is recommended to have some prior results from SEM and TEM and a clear idea about the features to be studied before proceeding for Atom Probe Tomography experiment. The sample preparation will be carried out using FIB at NFAPT, IIT Madras.

Instructions for Registration

Users should download and submit the LEAP research proposal to the lab before registration (Format Attached).

Internal user should register online by fowling link: http://saif.iitb.ac.in:8080/saif/OnlineReg/

The user must be available during the Atom Probe Tomography experiment. Preliminary literature survey has to be done for the respective experiment and the user must be aware of the parameters to be used for his samples. An appointment will be given as per the queue. The new user is requested to contact APT Lab before registration.

Charges for Internal users: Rs. 5000/- Sample (w.e.f. 1st May 2022)