# Effect of anisotropy distribution on local nucleation field in bistable ferromagntic microwires

## TL;DR

This paper analytically and numerically investigates how the distribution of anisotropy affects the local nucleation field in amorphous ferromagnetic microwires, emphasizing the importance of anisotropy gradient over average anisotropy.

## Contribution

It provides a new analytical and numerical approach to determine the nucleation field considering the detailed anisotropy distribution rather than averaged values.

## Key findings

- Nucleation field depends mainly on the steepness of anisotropy change at domain boundaries.
- Maximal anisotropy inside the wire is not a key factor for nucleation.
- The approach accounts for anisotropy distribution fully, improving understanding of magnetic switching.

## Abstract

Critical parameters defining the local nucleation field in amorphous ferromagnetic microwires with positive magnetostriction are obtained analytically through scaling procedures. Exact value of the nucleation field is obtained numerically as a function of geometric parameters of anisotropy distribution, which is fully taken into account instead of being averaged out. It is established that the value of nucleation field depends predominantly on the steepness of anisotropy change withing the boundary between axial and radial domains, while the maximal value of anisotropy inside the wire or an overall average is not relevant.