12C/13C ratio determination in nanodiamonds by atom-probe tomography

The astrophysical origins of similar to 3 nm-diameter meteoritic nanodiamonds can be inferred from the ratio of C-12/C-13. It is essential to achieve high spatial and mass resolving power and minimize all sources of signal loss in order to obtain statistically significant measurements. We conducted atom-probe tomography on meteoritic nanodiamonds embedded between layers of Pt. We describe sample preparation, atom-probe tomography analysis, 3D reconstruction, and bias correction. We present new data from meteoritic nanodiamonds and terrestrial standards and discuss methods to correct isotopic measurements made with the atom-probe tomograph. (C) 2015 Elsevier B.V. All rights reserved.