Boychuk Alexey N, Makarov Dmitriy V, Zakhlevnykh Alexander N
Physics of Phase Transitions Department, Perm State University, Bukirev St. 15, 614990, Perm, Russia.
Eur Phys J E Soft Matter. 2016 Oct;39(10):101. doi: 10.1140/epje/i2016-16101-y. Epub 2016 Oct 26.
We theoretically study the dynamics of the orientational structure of a ferronematic liquid crystal with soft planar coupling between the director and the magnetization in a rotating magnetic field. We determine critical parameters characterizing the boundary between synchronous and asynchronous rotation regimes. We show that the magnetic impurity increases the stability threshold of an asynchronous rotation regime. The critical angular velocity, the angles of the director and the magnetization rotation in each regime of orientational structure rotation are found for rigid planar coupling. We obtain that in weak magnetic fields when the main mechanism of the field influence on a ferronematic liquid crystal is associated with the effect on the magnetic particles, the critical angular velocity is linearly dependent on the field strength, while in strong magnetic fields, when the influence of a field is determined by a diamagnetic mechanism, the critical velocity is quadratically dependent on the field strength.
我们从理论上研究了在旋转磁场中，指向矢与磁化强度之间具有软平面耦合的铁磁向列型液晶取向结构的动力学。我们确定了表征同步和异步旋转状态之间边界的临界参数。我们表明，磁性杂质会提高异步旋转状态的稳定性阈值。对于刚性平面耦合，我们找到了每个取向结构旋转状态下的临界角速度、指向矢的角度和磁化强度旋转角度。我们得出，在弱磁场中，当磁场对铁磁向列型液晶的主要影响机制与对磁性粒子的作用相关时，临界角速度与场强呈线性关系；而在强磁场中，当磁场的影响由抗磁机制决定时，临界速度与场强呈二次关系。
