Barkhausen jumps and metastability

Abstract

The magnetization process drives a ferromagnetic system through a sequence of discrete metastable magnetization states; the abrupt transitions taking place between these states are responsible for the Barkhausen noise. In thin films, the magnetization states of a small region of the sample surface can be identified, and experimental information can be gained on the statistical properties of the magnetization sequence. Here we investigate the stability of the system in a particular state in the presence of an increasing magnetic field, which we call the state life. A simple statistical model, based on the reliability theory, is proposed in order to explain the observed data.

Switching dynamics of doped CoFeB trilayers and a comparison to the quasistatic approximation

“…Whenever the nanomagnets are sufficiently small or elongated, a series of magnetization plateaus and Barkhausen jumps are witnessed. 56 In experiments where Barkhausen jumps are investigated, the metastable states of the system have a relative stability and to make the transition to another metastable state, the system has to surmount an energy barrier. 57 The Zeeman energy dictates the transition between metastable states as the magnetic field is increased or decreased, but thermal fluctuations and the level of damping also hold sway (see Fig.…”

C60Monomer as an Inherently Monodisperse Standard Nanoparticle in the 1 nm Range

“…In BN experiments the escape from the initial state is determined by the increasing applied field H . A simple model has been presented [13] which explains the shape of P( H ). In this model a magnetic dipole mimics the complex magnetic system initially trapped in a potential well such as case A of figure 2.…”