Helios g4 uc

For an inside look at a biofilm and not only outer-rim observations, the same glasses coated with Cr that were used for HR-SEM were also analyzed with dual-beam HR-SEM. Areas meant for examination were locally coated with Pt and were sliced using focused ion beam. Biofilm’s inside was examined in Helios G4 UC Thermo Fisher Scientific scanning electron microscope operating at 5.00 kV.

Samples for FIB-SEM were prepared and observed as previously described (39 ). A mouse embryo at one-somite stage was collected in ice-cold PBS and fixed immediately at 4°C overnight in fresh 2% glutaraldehyde and 4% paraformaldehyde in 0.1 M sodium phosphate buffer (pH 7.0). It was then incubated in ice-cold 2% OsO₄ for 120 min and embedded in resin. After smoothing the surface of the embedding by ultramicrotome, the obtained specimen was observed with Helios G4 UC (Thermo Fisher Scientific).

A ThermoFisher Helios G4 UC FIB/SEM tool was used for preparing cross-section TEM samples. The as-received thin film samples were imaged by SEM for selecting a specific region of interest in the film. The film surface was protected from the ion beam with a 300 nm thick electron beam deposited layer of platinum (Pt) followed by a 2 μm layer of carbon/tungsten (C/W) ion beam deposition. Afterward, the surrounding area was milled around and beneath the region of interest using a 30 kV Ga beam. The protected volume (ca. 10 × 2 × 7 μm³) was lifted out using the Easylift micromanipulator and attached to a Cu TEM grid. The ion beam was further used to polish and thin the sample from both sides until it was suitably transparent to 30 keV electrons. Final thinning was carried out with a low kV beam (5 keV) to remove amorphous layers from the TEM sample surface, so the final thickness was ∼50 nm. Samples were fabricated from different locations and different substrate orientations. EDS measurements were carried out using a Bruker XFlash EDS system (60 mm SDD detector) mounted on the FIB/SEM tool.^{31 (link)}

The structures and compositions of MGT were characterized by SEM, TEM, XRD, FTIR, XPS, and Raman spectroscopy. TEM images were obtained using a JEM2100 transmission electron microscope operated at an accelerating voltage of 200 kV. HR-TEM images were taken using a JEM-2100F transmission electron microscope with an accelerating voltage of 200 kV. SEM measurements were performed using a field emission SEM (FEI Helios G4 UC) operated under UC (UniColore) mode at 1 kV + 1000 V UC. XRD patterns were measured by a D/max2550VB3+/PC x-ray diffractometer using Cu (40 kV, 100 mA). FTIR spectra were recorded on a Nicolet iS10 infrared spectrometer (Thermo Fisher Scientific, USA). XPS data were performed on an XPS (AXIS Ultra DLD, Japan) equipped with an Al Kα (1486.6-eV photons). SERS was performed on a Thermo Fisher Scientific DXR Raman microscope with a 10× [numerical aperture (NA), 0.4] microscope and a 10-mW laser power for SERS measurements.

The crystalline structure of the as-prepared material was characterized by powder X-ray diffraction (Scintag Pad-V XRD Powder Diffractometer, graphite monochromated Cu Kα radiation). Absorption spectra were collected using Agilent Cary 5000. SEM images were taken by the FEI Helios G4 UC dual field emission electron and Ga ion beam scanning electron microscope. Images were taken with an accelerating voltage of 5 kV. The thickness of the films was measured using the Bruker Dektak XT. The current–voltage (I–V) measurements were obtained by a Keithley 2400 integrated with LabView under a white light LED lamp with intensity of 100 mW cm⁻². The photovoltage-response time measurements were obtained using an NI-6210 DAQ. The signal from the DAQ (NI6210) to the computer was boosted with the Hamamatsu C7319 on low bandwidth setting and 105 gain and powered with an Agilent E3630A at 6 V. Matlab was used to collect and process the data. The light source was powered by a GwInstek GFG-8255A function generator, creating a square wave with an amplitude of 2 V to power a 585 nm LED of 37 mW cm⁻² intensity.