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

Abstract

In this work, thin hematite films (α-Fe2O3) were fabricated by laser-assisted chemical vapor deposition (LCVD) method using Ar+ laser source. The deposited α-Fe2O3 films were subjected to annealing treatment in O2 and N2 atmosphere at 350 and 400 °C, respectively. The obtained haematite films were doped by bombarding N-ions (3.63 × 1015–6.63 × 1015 ions/cm2) at 350 °C in a furnace at 350 °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 α-Fe2O3 films before and after N-ion at different fluences (0.63 × 1015–6.63 × 1015 ions/cm2) were studied by Rutherford backscattering (RBS) and atomic force microscopy (AFM). Hematite thin films had a rhombohedral structure and annealing of hematite films in N2 atmosphere at 350 °C, caused the formation of uniform surface topography with a lower surface roughness as compared to those annealed in O2 atmosphere. Besides, the hematite films doped with N2 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.