Sort J, Buchanan K S, Novosad V, Hoffmann A, Salazar-Alvarez G, Bollero A, Baró M D, Dieny B, Nogués J
Institució Catalana de Recerca i Estudis Avançats (ICREA) and Departament de Física, Universitat Autònoma de Barcelona, 08193 Bellaterra, Barcelona, Spain.
Phys Rev Lett. 2006 Aug 11;97(6):067201. doi: 10.1103/PhysRevLett.97.067201. Epub 2006 Aug 7.
The effect of imprinting symmetric and displaced vortex structures into an antiferromagnetic material is investigated in micron-sized disks consisting of exchange coupled ferromagnetic-antiferromagnetic bilayers. The imprint of displaced vortices manifests itself by the occurrence of a new type of asymmetric hysteresis loops characterized by curved, reversible, central sections with nonzero remanent magnetization. Such an imprint is achieved by cooling the disks through the blocking temperature of the system in small fields. Micromagnetic simulations reveal that asymmetric vortexlike loops naturally result from the competition between the different energies involved in the system.
在由交换耦合铁磁 - 反铁磁双层组成的微米级圆盘内，研究了将对称和位移涡旋结构印刻到反铁磁材料中的效果。位移涡旋的印刻表现为出现一种新型的不对称磁滞回线，其特征是具有弯曲、可逆且具有非零剩余磁化强度的中心部分。通过在小磁场中使圆盘冷却至系统的阻塞温度来实现这种印刻。微磁模拟表明，不对称的类涡旋回线自然地源于系统中不同能量之间的竞争。
