Magnetic properties of strontium hexaferrite films prepared by pulsed laser deposition

The magnetic properties of strontium hexaferrite (SrFe12O19) films fabricated by pulsed laser deposition on the Si(100) substrate with Pt(111) underlayer have been studied as a function of film thickness (50–700 nm). X-ray diffraction patterns confirm that the films have c-axis perpendicular orientation. The coercivities in perpendicular direction are higher than those for in-plane direction which indicates the films have perpendicular magnetic anisotropy. The coercivity was found to decrease with increasing of thickness, due to the increasing of the grain size and relaxation in lattice strain. The 200 nm thick film exhibits hexagonal shape grains of 150 nm and optimum magnetic properties of Ms=298 emu/cm3 and Hc=2540 Oe.

► The SrFe12O19 film deposited on Si(100) with Pt underlayer by pulsed laser deposition.
► The films deposited for different thicknesses at 700 °C.
► The crystallite size and c-axis dispersion increases, but lattice strain relaxes with thickness.
► The coercivity was found to decrease with increasing thickness.