Speaker
Description
The NanoSIMS is emerging as a powerful tool to study complex problems in materials science and, along with atom probe tomography, is one of the few techniques able to localise hydrogen and deuterium at microstructurally relevant length scales. The NanoSIMS is a high-resolution secondary ion mass spectrometry instrument capable of chemical mapping at <100 nm spatial resolution, detection limits in the ppm range and is able to detect almost all elements in the periodic table as well as isotopes. It uses a 16 kV Cs+ ion probe to generate secondary ions from the sample surface which are collected and analysed in a magnetic mass spectrometer. The NanoSIMS has seven detectors allowing simultaneous detection of different elements and isotopes along with an ion-induced secondary electron image giving topographical information.
In this presentation I will show how we have been using the NanoSIMS to localise deuterium in electrochemically charged steel and nickel alloys as well as in zirconium alloys oxidised in an autoclave to simulate nuclear reactor conditions. I will explain the requirement to use deuterium to minimise imaging artefacts and uncertainties in the origin of the detected hydrogen. The complexities associated with detecting hydrogen and deuterium in the NanoSIMS will be discussed and I will also show how NanoSIMS compares to the information that can be obtained with atom probe tomography in terms of spatial resolution and volume of material analysed.
