Explanation of permalloy structure

Introduction to permalloy:

Permalloy refers to iron nickel alloy with a wide range of nickel content, ranging from 35% to 90%. Permalloy is characterized by high permeability in weak magnetic field. Their saturation magnetic induction intensity is generally between 0.6-1.0t.

Magnetic materials with the continuous change of external magnetic field, an approximate closed curve formed by the relationship between magnetic induction intensity B and external magnetic field intensity H is called hysteresis loop, which generally refers to the characteristics of magnetic materials. The hysteresis loop of hard magnetic materials is hypertrophy and the soft magnetic is thin.

Structural magnetism of permalloy:

1. Permalloy is an iron nickel alloy with high permeability under weak magnetic field. Ferronickel alloys with nickel content of more than 30% have single-phase face centered cubic (V) structure at room temperature, but the single-phase structure near 30% Ni is very unstable. Therefore, the nickel content of practical iron nickel soft magnetic alloys is more than 36%.

2. When Fe Ni alloy contains 75% (atomic fraction) nickel, the long-range ordered transformation of Ni3Fe will occur in this single-phase alloy. At this time, the lattice constant and physical properties of the alloy, such as resistivity and magnetism, will change. Therefore, the effect of order transition on performance should be considered. Usually, a small amount of Mo or Cu and other additional elements are added to Ni3Fe alloy to inhibit the formation of long-range order.