Zero magnetostriction and extremely low residual magnetic loss in Fe-Co amorphous ribbons

Abstract

The initial permeability μ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">i</inf> the loss factor <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\tan\delta</tex> , and the inverse quality factor <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">\tan\delta/\mu_{i}</tex> of Fe <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</inf> Co <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">70</inf> Si <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">15</inf> B <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</inf> ribbons 35μm, 30μm, 25μm and 21μm in thickness were measured with a Maxwell Bridge from room temperature to 140°C in the high-frequency region from 3kHz to 500kHz. The initial permeability of the ribbon 21μm in thickness was about 10,600 at 3kHz and 4300 at 500kHz. The residual loss coefficient C <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> and the hysteresis loss coefficient h <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</inf> were extremely low, about <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8\times10^{-3}</tex> and 60(cm/A), respectively. In the high-frequency region, the eddy current loss term increases with the square of the thickness of the ribbons and plays the most important part of all the magnetic losses.