Friday, December 7, 2012

1212.1411 (L. Tosi et al.)

Barkhausen-type noise in the resistance of antiferromagnetic Cr thin
films
   [PDF]

L. Tosi, E. Osquiguil, E. E. Kaul, C. A. Balseiro
We present an experimental study of the changes generated on the electrical resistance $R(T)$ of epitaxial Cr thin films by the transformation of quantized spin density wave domains as the temperature is changed. A characteristic resistance noise appears only within the same temperature region where a cooling-warming cycle in $R(T)$ displays hysteretic behavior. We propose an analysis based on an analogy with the Barkhausen noise seen in ferromagnets. There fluctuations in the magnetization $M(H)$ occur when the magnetic field $H$ is swept. By mapping $M \rightarrow \Psi_0$ and $H \rightarrow T$, where $\Psi_0$ corresponds to the order parameter of the spin density wave, we generalize the Preisach model in terms of a random distribution of {\it resistive hysterons} to explain our results. These hysterons are related to distributions of quantized spin density wave domains with different sizes, local energies and number of nodes.
View original: http://arxiv.org/abs/1212.1411

No comments:

Post a Comment