Enhanced surface dynamics and magnetic switching of α-Fe2O3 films prepared by laser assisted chemical vapor deposition

In this work, thin hematite films (alpha-Fe2O3) were fabricated by laser-assisted chemical vapor deposition (LCVD) method using Ar+ laser source. The deposited alpha-Fe2O3 films were subjected to annealing treatment in O-2 and N-2 atmosphere at 350 and 400 degrees C, respectively. The obtained haematite films were doped by bombarding N-ions (3.63 x 10(15)-6.63 x 10(15) ions/cm(2)) at 350 degrees C in a furnace at 350 degrees C. The structure, optical, and magnetic properties were evaluated and compared by X-ray diffraction (XRD), Raman spectroscopy, ultraviolet-visible spectroscopy (UV Vis), and superconducting quantum interference device (SQUID) with vibration sample magnetometer (VSM). The surface topography and ripple formation on N-doped alpha-Fe2O3 films before and after N-ion at different fluences (0.63 x 10(15) -6.63 x 10(15) ions/cm(2)) were studied by Rutherford backscattering (RBS) and atomic force microscopy (AFM). Hematite thin films had a rhombohedral structure and annealing of hematite films in N-2 atmosphere at 350 degrees C, caused the formation of uniform surface topography with a lower surface roughness as compared to those annealed in O-2 atmosphere. Besides, the hematite films doped with N-2 had finer ripples across the surface which increased with higher nitrogen fluence. The photoconductivity mechanism of these films in various UV, Indigo, Green, and dark region is also reported here which can serve as a blueprint for material design in various photochemical, catalytic, and magnetic storage applications.

Automated summary

In this study, thin hematite films were fabricated using LCVD method and their structure, optical, and magnetic properties were evaluated after various treatments and dopings. Annealing in N-2 atmosphere at 350 degrees C resulted in lower surface roughness and uniform surface topography, while N-doping increased surface ripples on the film. The photoconductivity mechanism of these films in different regions was also studied, providing insights for material design in various applications.