Epitaxial Growth and Magnetic Properties of Half-Metallic Fe$_{3}$O$_{4}$ on Si(100) Using MgO Buffer Layer

Abstract

The growth and magnetic properties of epitaxial magnetite Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> on Si(100) using MgO buffer layer have been studied by reflection high-energy electron diffraction, X-ray photoelectron spectroscopy, and magneto-optical Kerr effect. The epitaxial Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> films were prepared by <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in situ</i> post growth annealing of ultrathin epitaxial Fe films at 220degC in an oxygen partial pressure of 8 times 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-4</sup> mbar. The epitaxial relationship was found to be Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> (100)lang001rang//MgO(100)lang001rang//Si(100)lang001rang with the MgO film grown cube-on-cube orientation with the Si substrate. While the Fe unit cell rotates 45deg to match that of the MgO buffer layer, it rotates 45deg back upon oxidation. A low saturation field has been observed indicating low density of antiphase boundaries.