Permalloy
Permalloy is a nickel–iron magnetic alloy, with about 80% nickel and 20% iron content. Invented in 1914 by physicist Gustav Elmen at Bell Telephone Laboratories, it is notable for its very high magnetic permeability, which makes it useful as a magnetic core material in electrical and electronic equipment, and also in magnetic shielding to block magnetic fields. Commercial permalloy alloys typically have relative permeability of around 100,000, compared to several thousand for ordinary steel.
In addition to high permeability, its other magnetic properties are low coercivity, near zero magnetostriction, and significant anisotropic magnetoresistance. The low magnetostriction is critical for industrial applications, allowing it to be used in thin films where variable stresses would otherwise cause a ruinously large variation in magnetic properties. Permalloy's electrical resistivity can vary as much as 5% depending on the strength and the direction of an applied magnetic field. Permalloys typically have the face centered cubic crystal structure with a lattice constant of approximately 0.355 nm in the vicinity of a nickel concentration of 80%. A disadvantage of permalloy is that it is not very ductile or workable, so applications requiring elaborate shapes, such as magnetic shields, are made of other high permeability alloys such as mu metal. Permalloy is used in transformer laminations and magnetic recording heads.
Podcasts:
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by Parmalee
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by Parmalee
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by Parmalee
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by Parmalee
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by Parmalee
Wash
by: ParmaleeEvery now and then I think about you Wondered how I’d ever live without
you Whenever I think I figured it out my reasons turn to shame so I wash
em down forget it now I wanted you to stay but I watched myself fall away
from you So lay me down if you’re broken hearted and let the sunlight
shine in I’ll hold you close if I think you’re falling so we wont burn out in
the end I still have your pictures I still wonder how you are I’ve heard
about you and how you fell apart and I know you’ve been wasting for so
long now and I’m sorry that I did nothing to turn you around I just
watched myself (watched myself) fall away from you lay me down if you’re
broken hearted and let the sunlight shine in I’ll hold you close if I think
you’re falling so we won’t burn out in the end Shouldn’t I learn a thing or
two shouldn’t I wake up next to you shouldn’t I be the one that said to
hold you hold you shouldn’t I shouldn’t I shouldn’t I shouldn’t I hold you
hold you lay me down if you’re broken hearted and let the sunlight shine
in I’ll hold you close if I think you’re falling so we wont burn out in the
end lay me down if you’re broken hearted and let the sunlight shine in I’ll
hold you close if I think you’re falling so we wont burn out in the end in