Gaia3

For the transmission electron microscopy (TEM) investigations, several lamellae from the same single crystal of Cr_1+δTe₂ were prepared by Focused Ion Beam (FIB) Ga⁺ ion milling [TESCAN GAIA3 operating at 30 kV ion-beam energy] using standard lift-out procedures. Final polishing of the lamellae was performed with lower Ga⁺ ion-beam energies (5 kV) to reduce the thickness of any amorphous surface layers. The thickness, t, of the lamella was measured using Energy Filtered TEM (EFTEM) by the log-ratio method from the relationship, t = λ ln (I_t/I₀), where λ is the total inelastic mean free path of the electrons, and I_t and I₀ are the total and zero-loss intensities in the EELS spectrum, respectively^{43 (link)}. The error in measuring t is ~10 %. Magnetic textures were investigated by TEM [FEI TITAN 80-300] in the Lorentz mode operated at an accelerating voltage of 300 kV using a GATAN double-tilt sample holder which is capable of varying the temperature between 100 and 368 K. A vertical magnetic field was applied to the lamella within the TEM column by passing currents through the coils of the objective lens and a Lorentz mini-lens was used for imaging.

FIB–EDS mapping analyses of the natural lake BSi were carried out to reveal the Al and Si distributions in the BSi samples. This process was achieved using a FIB–SEM (GAIA3, Tescan) equipped with a Triglav FESEM column, a Cobra FIB column, a multichannel gas injection system, and an Oxford Instrument X-Max 80 Aztec energy-dispersive X-ray spectrometer. A single frustule of BSi selected for characterization was picked using a nanomanipulator (Oxford OmniProbe 400), and the sample surface was milled using a focused gallium ion (Ga⁺) beam with an accelerating voltage of 30 kV, a current of 1.0 nA, and a total milling time of 1 min.

X-ray diffraction (XRD; SmartLab 9 kW (Rigaku Corporation, Tokyo, Japan)) was applied to analyze the phases of the PEO coatings. The XRD used Kα radiation with a Copper (Cu) target in steps of 0.02° and a scan range of 10° to 90° at 6 kV. The GIXRD (SmartLab 9 kW) was taken to determine the phase of the anodic oxide film. The grazing incidence angle was 0.5° and the rest of the parameters were unchanged. The thicknesses of the coatings were measured using a micrometer (model Art. Nr.64200) and an optical microscope (Olympus-BH, Shinjuku, Japan). This microscope was also used to examine the surface morphologies of the coatings and measure their roughness. Figure 2 shows a representation of the thickness parameters. The surface, cross-sectional properties and morphology of the PEO coatings were obtained using a focused ion beam (SEM; TESCAN GAIA3, Brno, The Czech Republic).

The surface morphology of the composite microspheres was studied by scanning electron microscopy (SEM) (GAIA3, Tescan, Brno, Czech Republic). The lyophilized microspheres were coated with a gold layer for enhancing conductivity. Attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectrophotometer (Diffuse Reflectance, Thermo model-NICOLET-IS 10 FTIR) was conducted to characterize the functional groups of microspheres. The ATR-FTIR spectra of the composite microspheres were recorded from 4000 to 500 cm⁻¹. Particle sizes were measured using an optical microscope fitted with a micrometer by which the size of the microspheres could be determined. In order to calculate the average size properly, fifty composite microspheres of all formulations were used in these measurements [19 (link)].

FTIR spectroscopy was used to assess the functional groups present in raw lignite and BLA before and after adsorption. After drying, the lignite samples and KBr were ground into powders (diameter < 2 µm). The lignite power and KBr were mixed with a ratio of 1:200 (w/w) and then pressed into sheets using a tableting machine. Finally, the pressed sheets were scanned using light with wavelengths of 4000–550 cm⁻¹ and a resolution of 1 cm⁻¹. Each sample was scanned 32 times [35 ,48 (link),49 (link)].
The differences in the surface morphology of the BLA before and after microbial modification and the adsorption of heavy metal ions were investigated via SEM/EDS. The samples were washed with anhydrous ethanol and dispersed, fixed on a conductive adhesive surface, naturally air-dried, and then characterized using field-emission SEM/EDS (FE-SEM; Tescan GAIA3, Tescan company, Jebrno, Czech Republic) [50 (link)]. The elemental composition of the lignite samples was investigated using an element analyzer (PE PerkinElmer 2400; Perkin-Elmer, Waltham, MA, USA).