Technical Datasheets Introduced For 3 Dimensional Atom Probe

Oxford nanoScience Ltd has introduced a series of technical datasheets covering a variety of aspects of 3 Dimensional Atom Probe (3DAP) usage, ranging from sample preparation techniques to technical issues and application examples.

The first three datasheets are entitled: ‘Electropolishing methods for bulk samples’, ‘Mass resolution of maraging steel’ and ‘Cluster analysis’ and are available for download as PDF files in the ‘technical library’ section at www.ons3dap.com.

‘Electropolishing methods for bulk samples’ gives practical information for the two-stage electropolishing preparation of samples for the 3DAP from bulk metal sample blanks with a circular or square cross section (wires, sheets, ribbons etc). Details are provided on the chemicals and conditions required for the preparation of more than 40 different materials.

‘Mass resolution of maraging steel’ looks at factors that affect resolution in the 3DAP and uses an example of a maraging steel to illustrate the importance of measuring resolution at full width thousandth maximum (FW0.1%M). In this example, adjacent Cu2+ and Mo3+ peaks separated by only 0.17 amu with a count of around just 20 ions can be resolved even when the main iron peak count is 60,000 ions.

‘Cluster analysis’ examines important factors in the way the 3DAP software identifies clusters samples caused by processes such as age hardening or irradiation damage. The methodology used in the POSAP materials characterization software is reviewed, with examples from nanometre scale clusters precipitated in high copper steels used in reactor vessels during irradiation.

The 3DAP allows a sample to be analysed to produce a 3-dimensional map showing both the position and chemical identity of individual atoms within the sample. The extra-ordinary resolution offered by the technique allows a huge range of materials to be characterized at the nanoscale level. Two versions of the instrument are available. A voltage pulsed system is suitable for use with conducting samples such as metals and alloys, whilst the recently introduced laser system extends the range of samples to include semiconductor materials.