T=0 phase diagram and nature of domains in ultrathin ferromagnetic films with perpendicular anisotropy
| Autor: | Daniel A. Stariolo, Orlando V. Billoni, Sergio A. Cannas, Santiago Alberto Pighin |
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| Jazyk: | angličtina |
| Rok vydání: | 2010 |
| Předmět: |
Physics
Condensed Matter - Materials Science Condensed matter physics Condensed Matter - Mesoscale and Nanoscale Physics Heisenberg model Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences Disordered Systems and Neural Networks (cond-mat.dis-nn) Parameter space Condensed Matter - Disordered Systems and Neural Networks Condensed Matter Physics Electronic Optical and Magnetic Materials Magnetization Ferromagnetism Mesoscale and Nanoscale Physics (cond-mat.mes-hall) Ising model Anisotropy Ground state Phase diagram |
| Popis: | We present the complete zero temperature phase diagram of a model for ultrathin films with perpendicular anisotropy. The whole parameter space of relevant coupling constants is studied in first order anisotropy approximation. Because the ground state is known to be formed by perpendicular stripes separated by Bloch walls, a standard variational approach is used, complemented with specially designed Monte Carlo simulations. We can distinguish four regimes according to the different nature of striped domains: a high anisotropy Ising regime with sharp domain walls, a saturated stripe regime with thicker walls inside which an in-plane component of the magnetization develops, a narrow canted-like regime, characterized by a sinusoidal variation of both the in-plane and the out of plane magnetization components, which upon further decrease of the anisotropy leads to an in-plane ferromagnetic state via a spin reorientation transition (SRT). The nature of domains and walls are described in some detail together with the variation of domain width with anisotropy, for any value of exchange and dipolar interactions. Our results, although strictly valid at $T=0$, can be valuable for interpreting data on the evolution of domain width at finite temperature, a still largely open problem. 7 pages, 4 figures. Short version of arXiv:0907.5153, accepted for publication in JMMM (2010) |
| Databáze: | OpenAIRE |
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