BSE and EBSD measurements of 7d hydrated alite

A 7d hydrated alite (C₃S) was embedded, mechanically polished and finally cleaned using an Argon broad ion beam device. This specimen was then imaged using an SEM (Helios G4 UX by Thermo Fisher Scientific) at overlapping positions. The locations of the EBSD measurements relative to the BSE data are illustrated in BSE-EBSD-positions.jpg.

The dataset contains a large SEM-BSE images which was acquired at 15 kV, 1.6 nA using Maps 3.10 by Thermo Fisher Scientific. It is available as the Maps-project file (C3S_7d_BSE_Maps.7z) and as pre-stitched TIF (C3S_7d_BSE_stitched.7z). The stitched file has a resolution of 38675 x 51594 px at a pixel size of 112.4101 nm/px (total area of 4.35 x 5.8 mm²). It was chosen to be this large to enable a large area of possible EBSD measurement positions.

The EBSD data is available in 3 different formats:

• Oxford Instruments AZtec 4.3 project file (*.oip/*.oipx, within RAW_EBSD_Oxford_Aztec_oip_oipx.7z). These are vendor-specific files, for which the software Aztec is required.
• Oxford Instruments NanoAnalysis HDF5 file format (*.h5oina within RAW_EBSD_Oxford_AztecCrystal_h5oina.7z). These are vendor-specific (AZtecCrystal 3.2) files based on the hdf5 format which has public specification. The data contained in this format are preprocessed and cleaned up.
• Channel Text Files (*.ctf) are an ASCII Format, which can be easily read using Python libraries (e.g. orix). The data contained in this format are preprocessed and cleaned up.

The 3 EBSD measurements (A: "site 3", B: "site 4", C: "site 5") were done at 15 kV, 1.6 nA at a step size of 2 µm/px. During the cleanup/preprocessing step, pseudosymmetries were removed. The identification of the alite crystals was done using the crystal structure of the M3 polymorph (COD 1540705, ICSD 94742).

The EBSD measurements were aligned to the BSE image using QGIS 3.42. The respective QGIS project containing the aligned and raw EBSD datasets (using the band contrast images) and their respective point-pairs is available in QGIS_BSE-EBSD-alignment.7z.