The isotropic to ferroelectric nematic liquid transition had been theoretically studied over one hundred years ago, but its experimental studies are rare. Here we present polarizing optical microscopy studies and theoretical considerations of ferroelectric nematic liquid crystal droplets coexisting with the isotropic melt. We find that the droplets have flat pancake-like shapes that are thinner than the sample thickness as long as there is a room to increase the lateral droplet size. In the center of the droplets a wing shaped defect with low birefringence is present that moves perpendicular to a weak in-plane electric field, and then extends and splits in two at higher fields. Parallel to the defect motion and extension, the entire droplet drifts along the electric field with speed that is independent of the size of the droplet and is proportional to the amplitude of the electric field. After the field is increased above 1V/mm the entire droplet gets deformed and oscillates with the field. These observations led us to determine the polarization field and revealed the presence of a pair of positive and negative bound electric charge due to divergences of polarization around the defect volume.

中文翻译：

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各向同性熔体中的铁电向列液滴

一百多年前，理论上已经研究了各向同性向铁电向列相的液体转变，但其实验研究很少。在这里，我们介绍了与各向同性熔体共存的铁电向列液晶液滴的偏光光学显微镜研究和理论考虑。我们发现，只要有增加横向液滴尺寸的空间，液滴就具有比样品厚度更薄的扁平煎饼状形状。在液滴的中心，存在具有低双折射的翼状缺陷，该缺陷垂直于弱的面内电场移动，然后在更高的场中延伸并分裂成两部分。平行于缺陷的运动和延伸，整个液滴沿电场漂移，速度与液滴大小无关，与电场幅度成正比。电场增加到 1V/mm 以上后，整个液滴变形并随电场振荡。这些观察使我们确定了极化场，并揭示了由于缺陷体积周围的极化发散而存在一对正负束缚电荷。