New non-magnetostrictive metallic glass

Abstract

A new metallic glass, (METGLAS <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">®</sup> alloy) Co <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">74</inf> Fe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> B <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</inf> , has been identified which exhibits ∼ zero magnetostriction ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">|\lambda_{s}|&lt;0.4\times10^{-6}</tex> ). The saturation induction of this new alloy, 11.8 kG, is approximately twice that reported for other non-magnetostrictive glasses with similar transition-metal (TM) content but including the metalloids P and Al or Si in addition to B. This larger magnetization results from the weaker hybridization of the TM d-bands with the valence bands of boron than with those of other metalloids. Due to the absence of magnetostriction, no coupling between winding stresses and magnetic properties exists. Hence, as-quenched/as-wound toroids of Co <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">74</inf> Fe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</inf> B <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">20</inf> glass exhibit exceptional low-field magnetic properties: <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">H_{c} = 0.035</tex> Oe, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B_{r} = 9800</tex> gauss and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\mu_{max} = 280,000</tex> .