Magnetocrystalline Anisotropy and Magnetostriction for Fe-(4 to 6 wt%) Si-(2 to 5 wt%) Al Alloy Single Crystals

Abstract

The temperature dependences of the magnetocrystalline anisotropy constant K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> and the magnetostriction constants λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">100</sub> and λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">111</sub> were measured for Fe-Si-Al alloy single crystals in the composition range 4 to 6 wt% Si, 2 to 5 wt% Al, balance Fe, after being slowly cooled from 1200°C or quenching from 1200°C. The crystal structure of these single crystal samples was determined by electron diffraction. The large difference in the magnitudes of K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> =9.1×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> erg/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> for 4.8 wt% Si, 5.0 wt% Al, bal. Fe alloy, and K <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sub> =9.1×10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> erg/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> for 4.7 wt% Si, 3.8 wt% Al, bal. Fe alloy was found to be connected with the difference in their crystal structures. The λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">100</sub> =0 and λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">111</sub> =0 equal-value line were identified on a composition diagram. The concentration of the alloy at which the second peak in μm occurs is located along the λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">100</sub> = 0 line Moreover, this second peak alloy may have the Do <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> structure.