Titan themis

The phase purity and crystal structure of the prepared perovskites was confirmed by room temperature XRD by using a PANalytical Empyrean X-ray diffractometer operated in reflection mode. High-resolution secondary and backscattered electron images were obtained using a FEI Scios scanning electron microscope (SEM). This instrument also served for the preparation of a thin lamella by focused ion beam (FIB).
Transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis and electron energy loss spectroscopy (EELS) analysis were carried out on a FEI Titan Themis instrument. He-ion microscopy (HIM) was carried out at Newcastle University on a Zeiss ORION NanoFab instrument, using a 25 keV He⁺ beam with 0.2 pA beam current to image sample ${\mathrm{CoNi\mid }}_{\mathrm{P}}^{\mathrm{10}}$ .
X-ray photoelectron spectroscopy (XPS) was carried out at two locations using monochromatic Al X-ray sources. At Newcastle University Thermo Scientific K-Alpha instrument was used while at Sasol, a Kratos Axis Ultra-DLD photoelectron spectrometer. The data were analysed using CasaXPS software. Quantification was performed based on the area of peaks of interest (Ce 3p, La 3d_5/2, Ti 2p, Co 2p) after the subtraction of background of appropriate shape.

An X-ray equipment ISO-DEBYEFLEX 3003, operating with a short anodic tube source producing Co Kα radiation (λ = 1.788965 Å, 40 kV, and 30 mA), were used to carry out the X-ray diffraction (XRD) measurements. Electron backscatter diffraction (EBSD) measurements were performed in a Zeiss-Crossbeam XB 1540 FIB scanning electron microscope. The characterization of the deformation microstructure by electron channeling contrast imaging (ECCI) and the analysis of the fracture morphology were performed using a Zeiss-Merlin high-resolution field emission electron microscope. The atom probe tomography (APT) tips were produced via a focussed ion beam (FIB, FEI Helios Nanolab 600i) from suited regions of interest containing grain boundaries that were beforehand revealed by a preceding EBSD scan. The elemental distributions of the recrystallized alloy were investigated using APT (LEAP 3000X HR, Cameca Inc.) operated under voltage-pulsed mode. TEM foil samples were prepared by a FIB lift-out procedure, imposing a final cleaning voltage of 5 kV. HAADF scanning transmission electron microscopy (STEM) imaging was conducted in an aberration-corrected FEI Titan Themis. The acceleration voltage was 300 kV. A probe semi-convergence angle of 17 mrad with inner and outer semi-collection angles of the annular detector from 73 to 350 mrad were selected to obtain the high-resolution imaging.

To analyze the structural quality of the devices, cross-sectional lamellas from five different devices were investigated. The lamellas were prepared using a FEI Helios Nanolab 450S focused ion beam. The cut was performed along the growth direction to reveal the Si seed and its nucleation interface with the III–V material. The lamellas were further investigated by STEM using two different instruments. High resolution images were generated using a double spherical aberration-corrected JEOL JEM-ARM200F microscope operated at 200 kV, while the EDS spectrum image was acquired with a FEI Titan Themis operated at 300 kV and equipped with ChemiSTEM technology. The EDS spectrum image was recorded with a beam current of 1.5 nA, 0.8 nm pixel spacing, and a dwell time of 4 μs pixel⁻¹. The elemental maps were calculated from the EDS spectrum image using the In Lα₁, Ga Kα₁, and Ga Kα₁ lines. Additional element maps can be found in Supplementary Note 3.

Phase identification and morphology observation of TCP phases were carried out using TEM. HRSTEM was used to observe the structures of different TCP phases and their internal composite defects at atomic level and capture a snapshot of the core of the climbing dislocation during the phase transformation process.
Tecnai T20 TEM, which has a double tilt sample holder for structural analysis, was set at 200 kV. Atomic resolution, Z-contrast (caused by the differences in atomic numbers), imaging [through HAADF-HRSTEM] was performed in a FEI Titan Themis spherical aberration-corrected microscope operating at 300 kV.
The samples were cut to 300-μm-thick slices via electrical discharge machining, and polished to 80 μm with silicon carbide paper. The specimens with 3 mm diameter were punched out mechanically and grounded to around 25 μm in thickness. Using an electrolyte solution of 10% perchloric acid and 90% ethyl alcohol, the foils’ thicknesses were further reduced for TEM observations through twin-jet electrochemical polishing at –20 °C. The HAADF-STEM image simulations were carried out via QSTEM software²⁸ .