Symmetry ebsd detector

EBSD data were collected at the Microscopy and Microanalysis Facility, John de Laeter Centre, Curtin University, using a Tescan MIRA3 SEM with Oxford Instruments Symmetry EBSD detector. Data were collected at 20 kV and ~1 nA beam current, with an analytical step size of 2 μm. EBSD data were collected using Oxford Aztec 4.1 acquisition software. Data were noise reduced using a wildspike and 5 nearest neighbor zero solution algorithm in Oxford Instruments Channel 5.12 software. Channel 5.12 was also used to create misorientation maps used to investigate the microstructural relationship between spinel core and rim. Relatively poor-indexing of the spinel represents the difficulty in polishing the analyzed grains after laser-ablation analysis.

SEM imaging and EBSD analysis were carried out using a Zeiss Sigma VP Electron Microscope (FEG SEM) at the OMNI Centre at the University of Otago. Backscatter images were acquired on carbon-coated thin sections using an acceleration voltage of 15 kV and an aperture of 120 µm. Electron Dispersive Spectroscopy (EDS) analysis, used to determine the chemical composition of mineral phases, was performed with an HKL INCA Premium Synergy Integrated EDS/EBSD system (Oxford Instruments). For EDS analysis the following conditions were used: acceleration voltage of 15 kV, aperture of 120 µm and a working distance of 8.5 mm in high vacuum mode. EBSD diffraction patterns were collected with a Symmetry EBSD detector (Oxford instruments) on SYTON polished and carbon-coated thin sections using an accelerating voltage of 30 kV and an aperture of 300 µm resulting in a beam current of 100 nA. Crystallographic orientation maps, phase maps, and band contrast images were acquired using AZTEC software (Oxford Instruments). Post-acquisition data processing and analyses (e.g., crystallographic preferred orientation (CPO), misorientation profiles) were performed with Channel5 software.