The invention discloses low-cost high-
conductivity magnet based amorphous nanocrystalline magnetically soft
alloy and a preparation method thereof. The molecular formula of the magnetically soft
alloy is FeaSibBcMdCueNbfM'g, wherein M is Al or Zn, and M' is selected from one or more of Y, Gd or Er; and a, b, c, d, e, f and g are the
mass percent, the value ranges meet the conditions that a is larger than or equal to 79 and less than or equal to 88.5, b is larger than or equal to 8 and less than or equal to 11, c is larger than or equal to 0.05 and less than or equal to 2, d is larger than or equal to 0.8 and less than or equal to 1.5, e is larger than or equal to 0.7 and less than or equal to 2.5, f is larger than or equal to 2 and less than or equal to 4, and g is larger than or equal to 0.008 and less than or equal to 0.02. On the basis that the high magnetic
conductivity, high Bs and low coercive force and consumption of the magnetically soft
alloy are all achieved, the low-cost Al or the Zn is adopted to replace
copper partially, the content of Nb is decreased, and trace rare-earth
metal is mixed, so that the production cost is reduced. The low-cost high-
conductivity magnet based amorphous nanocrystalline magnetically soft alloy is obtained through the preparation method which is simple in process and disclosed by the invention.