arXiv subjects

H. Mahboub

Publications and source records attributed to H. Mahboub.

2 recordsLinked to original sources

arXiv2004

Blume-Emery-Griffiths Model in a Random Transverse Field

The effect of the random quantum transverse field $Ω$ on the tricritical behavior of the spin-1 Blume- Emery- Griffiths (BEG) model is studied using effective field theory. It is found, that the tricritical behavior depends on both the biquadratic interaction $K$, single- ion anisotropy $Δ$, and the concentration $p$ of the disorder of $Ω$. Indeed, there exist a special value $p_{1}$ of the probability $p$ below which the tricritical behavior disappears.

cond-mat.dis-nn↗

arXiv2004

Surface anisotropy in nanomagnets: transverse or Néel ?

Through the hysteresis loop and magnetization spatial distribution we study and compare two models for surface anisotropy in nanomagnets: a model with transverse anisotropy axes and Néel's model. While surface anisotropy in the transverse model induces several jumps in the hysteresis loop because of the cluster-wise switching of spins, in the Néel model the jumps correspond to successive {\it coherent partial rotations} of the whole bunch of spins. These calculations together with experimental results suggest that Néel's model for surface anisotropy is more appropriate.

cond-mat.mtrl-sci↗