Permalloy were found in the electronics industry. Other compositions Other compositions of permalloy are available, designated by a numerical prefix denoting the percentage of nickel in the alloy, for example "45 permalloy" means an alloy containing 45% nickel, and 55% iron. "Molybdenum permalloy" is an alloy of 81% nickel, 17% iron and 2% molybdenum. The latter was invented at Bell Labs in 1940. At the time, when used in long distance copper telegraph lines, it allowed a tenfold increase in maximum line working speed. Supermalloy, at 79% Ni, 16% Fe, and 5% Mo, is also well known for its high performance as a "soft" magnetic material, characterized by high permeability and low coercivity. See also Loading coil Mu-metal Sendust Supermalloy (a material with even higher magnetic permeability) Notes References Richard M. Bozorth, Ferromagnetism, Wiley-IEEE Press (1993 reissue), . P. Ciureanu and S. Middelhoek, eds., Thin Film Resistive Sensors, Institute of Physics Publishing (1992), . Nickel alloys Magnetic alloys Ferromagnetic materials