Stripe pattern formation in phase separation accompanying orientational ordering under an external field
Stripe pattern formation in phase separation accompanying orientational ordering under an external field
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DOI：
10.1088/0953-8984/18/22/l05
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发表时间：
2006-06-07
影响因子：
2.7
通讯作者：
Tanaka, Hajime
中科院分区：
文献类型：
--
作者：
Araki, Takeaki;Tanaka, Hajime
我们以各向同性液体和向列液晶的混合物为例，证明了在相分离过程中伴随取向有序的场诱导条纹域的形成。我们可以将由保守组分和非保守取向有序耦合支配的旋量分解分为各向同性和各向异性两类。在前者中，相分离发生在取向有序之前。因此，即使在外场下，在早期阶段也形成各向同性相分离图案。在后者中，另一方面，在外场作用下相分离之前形成均匀取向相。然后通过相分离生长各向异性畴。揭示了二维有序参数空间的动力学路径是场致条纹形成的关键。这一原理通常适用于混合物，其中一个组分具有定向有序，如自旋、偶极或轨道有序。我们还证实了各向异性图案具有施加外场的方向记忆，这可能用于器件应用。
We demonstrate field-induced formation of stripe domains in phase separation accompanying orientational ordering, taking a mixture of an isotropic liquid and a nematic liquid crystal as an example. We can classify spinodal decomposition, which is governed by coupling between conserved compositional and non-conserved orientational ordering, into two types: isotropic and anisotropic spinodal decomposition. In the former, phase separation occurs prior to orientational ordering. Thus, an isotropic phase-separated pattern is formed in the early stage even under an external field. In the latter, on the other hand, a homogeneous oriented phase is formed prior to phase separation under an external field. Then anisotropic domains grow by phase separation. We reveal that the kinetic pathway in the two-dimensional order parameter space is key to field-induced stripe formation. This principle may be commonly applied to a mixture, one of whose components has orientational ordering such as spin, dipolar or orbital ordering. We also confirm that the anisotropic pattern has a memory of orientation of the applied external field, which may be used for device applications.