Hematite thin films: growth and characterization

Abstract

We have grown hematite (α − Fe 2 O 3 ) thin films on stainless steel and (001)-silicon single-crystal substrates by RF magnetron sputtering process in argon atmosphere at substrate temperatures from 400 to 800 • C. Conversion Electron Mössbauer (CEM) spectra of the sample grown on stainless steel at 400 • C exhibit values for hyperfine parameter characteristic of bulk hematite phase in the weak ferromagnetic state. Also, the relative line intensity ratio suggests that the magnetization vector of the polycrystalline film is aligned preferentially parallel to the surface. The X-ray diffraction (XRD) pattern of the polycrystalline thin film grown on steel substrates also corresponds to α − Fe 2 O 3 . The samples were also analyzed by Atomic Force Microscopy (AFM), those grown on stainless steel reveal a morphology consisting of columnar grains with random orientation, given the inhomogeneity of the substrate surface.

Advances in Engineered Metal Oxide Thin Films by Low-Cost, Solution-Based Techniques for Green Hydrogen Production

“…For instance, nanostructuring [45][46][47], surface modifiers [48][49][50], and dopant addition [51][52][53], among others, have been reported and reviewed in the literature to derive synergic approaches capable of increasing the photocurrent benchmarks closer to the theoretical values, and to accomplish the industry-required STH efficiency. Moreover, various fabrication methods have also been developed for increasing this benchmark, including pulsed laser deposition (PLD) [54,55], reactive sputtering [56][57][58], chemical vapor deposition (CVD) [59,60], electrodeposition [61][62][63][64], solvothermal [65][66][67], hydrothermal [68][69][70][71][72], and sol-gel-based approaches [73][74][75][76]. From a simple search in the Scopus (Elsevier) database, displayed in Figure 2, it can be seen that hydrothermal and sol-gel synthesis is involved in ~80% of the reports, whereas others only represent ~20%.…”