Permalloy is a nickel–iron magnetic alloy, with about 80% nickel and 20% iron content. Permalloy was invented in 1914 by physicist Gustav Elmen and 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. In addition to high permeability, permalloy's 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 is used in transformer laminations and magnetic recording heads.
Magnetic sensors is one of the areas that Permalloy (Ni-Fe-Mo) Sputtering Targets (Size:2'' ,Thickness:0.125'') can be used. Magnetic sensors were of great interest in electrical engineering and biomedical research during the past four decades. The existence of many types of magnetic field sensors is a consequence of very broad technological demands. For each particular application a combination of particular parameters is required, among which one can mention sensitivity with respect to the applied field, full-scale range, linearity, hysteresis, temperature coefficient of sensitivity, bias stability, offset features, noise, resistance to environmental factors, power consumption, size, cost, long-term stability etc.
For magnetic sensors based on thin film multilayered structures, which are promising nanomaterials for weak magnetic field sensors, and especially biosensors, the long-term stability is an underdeveloped area with very few studies. Here, it is necessary to distinguish thermal treatments at elevated temperatures for relaxation and modification of the effective magnetic anisotropy and sensitive element response at different temperatures. In the first case all measurements are done at room temperature but, in the second, they are measured for different elevated temperatures. Selected non-systematic data on the temperature dependence of giant magneto-impedance (GMI) of wires, amorphous, and nanocrystalline ribbons can be also found in the literature and, very recently, this point become a hot spot of interest.
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