Liu Liping, Sharma Pradeep
Department of Mechanical & Aerospace Engineering and Department of Mathematics, Rutgers University, Piscataway, New Jersey 08854, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2013 Oct;88(4):040601. doi: 10.1103/PhysRevE.88.040601. Epub 2013 Oct 10.
Magnetoelectric coupling-the ability of a material to magnetize upon application of an electric field and, conversely, to polarize under the action of a magnetic field-is rare and restricted to a rather small set of exotic hard crystalline materials. Intense research activity has recently ensued on materials development, fundamental scientific issues, and applications related to this phenomenon. This tantalizing property, if present in adequate strength at room temperature, can be used to pave the way for next-generation memory devices such as miniature magnetic random access memories and multiple state memory bits, sensors, energy harvesting, spintronics, among others. In this Rapid Communication, we prove the existence of an overlooked strain mediated nonlinear mechanism that can be used to universally induce the giant magnetoelectric effect in all (sufficiently) soft dielectric materials. For soft polymer foams-which, for instance, may be used in stretchable electronics-we predict room-temperature magnetoelectric coefficients that are comparable to the best known (hard) composite materials created. We also argue, based on a simple quantitative model, that magnetoreception in some biological contexts (e.g., birds) most likely utilizes this very mechanism.
磁电耦合——一种材料在施加电场时能够磁化，反之，在磁场作用下能够极化的能力——十分罕见，并且仅限于一小部分奇特的硬晶体材料。最近，人们针对与这种现象相关的材料开发、基础科学问题及应用展开了密集的研究活动。这种诱人的特性如果在室温下具有足够的强度，便可用于为下一代存储设备铺平道路，如微型磁性随机存取存储器和多态存储位、传感器、能量收集、自旋电子学等等。在本快速通信中，我们证明了一种被忽视的应变介导非线性机制的存在，该机制可用于在所有（足够）柔软的介电材料中普遍诱导出巨磁电效应。对于例如可用于可拉伸电子器件的软质聚合物泡沫，我们预测其室温磁电系数与已制造出的最知名（硬）复合材料相当。我们还基于一个简单的定量模型提出，在某些生物环境（如鸟类）中的磁感受很可能利用的正是这一机制。
