Titan g2 80 200 chemistem

The AFM images were acquired in tapping mode with Veeco DI3100. The XRD data were taken using a monochromated Cu-K_α source on a Bruker AXS D8-Discover. Cross-sectional specimens for STEM investigations were prepared by a FEI Quanta 3D FEG Focused Ion Beam. STEM images were acquired using a spherical aberration-corrected microscope equipped with four Super-X EDS detectors (FEI Titan G2 80-200 Chemi STEM, 30 mrad convergence angle).

Atomic resolution high-angle annular dark field (HAADF) scanning transmission electron microscopy (STEM) was carried out. Planar view samples (observation along the [001] direction) and cross-sectional view samples (observation along the [010] direction) were prepared by focused ion beam (FIB) (FEI Quanta 3D FEG) for observation by transmission electron microscopy. In consideration of the damage caused by ion beam in FIB, we used low voltage and beam current of 2 kV/27 pA. The observations were performed by spherical aberration-corrected electron microscopy on a FEI Titan G2 80–200 ChemiSTEM (30 mrad convergence angle, 0.8 Å spatial resolution), equipped with Super-X energy-dispersive X-ray spectroscopy (EDS) with four windowless silicon-drift detectors. The positions of the atomic columns in the images were confirmed by a mathematical method involving Gaussian Fitting based on MATLAB. Polarization mapping was performed by calculating ion displacements in the HAADF-STEM images. The microscopy data for quantitative analysis were acquired under the condition of the sample drifting less than 1 Å min⁻¹. Atomic-resolution EDS mapping was performed with an electron beam current of ~100 pA and a dwell time of 10 μs per pixel.

The experimental material was Ti-10Mo (wt. %) alloy, which was first solution treated at 1000 °C for 1 h and aged at 600 °C for 10 min to obtain a dual-phase structure with coexistence of α and β phases, then followed by quenching to room temperature. The thin TEM specimens were fabricated by using a FEI Quata 3D FEG type dual-beam focused ion beam (FIB) instrument. The atomic structure of the TiMo alloy specimen was characterized by spherical aberration-corrected scanning transmission electron microscopy (FEI Titan G2 80–200 ChemiSTEM) with an accelerating voltage of 200 kV. The TEM samples for the in-situ tensile test were thinned by PIPS instrument in order to obtain electron-transparent area. The specimen was adhered to a substrate at ambient temperature and placed for 24 h. Lastly, the specimen was strained by using a Gatan 671 low-temperature tensile holder at ambient temperature in a FEI Tecnai G2 F20 S-TWIN TEM with an accelerating voltage of 200 kV. The micro-pillars for the compression tests were prepared using the above FIB instrument and the pillars were processed into three sizes (0.5 μm, 1 μm and 3 μm, respectively). The in-situ compression experiments were performed in FIB with a Hysitron PI 87 micro-indenter in a displacement-control mode and the displacement rate was 5 nm/s.