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arXiv · 1407.8349

Twist-bend nematic liquid crystals in high magnetic fields

P. K. Challa·V. Borshch·O. Parri·C. T. Imrie·S. N. Sprunt·J. T. Gleeson·O. D. Lavrentovich·A. Jakli
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Abstract

We present magneto-optic measurements on two materials that form the recently discovered twist-bend nematic (Ntb) phase. This intriguing state of matter represents a new fluid phase that is orientationally anisotropic in three directions and also exhibits translational order with periodicity several times larger than the molecular size. NTB materials may also spontaneously form a visible, macroscopic stripe texture. We show that the optical stripe texture can be persistently inhibited by a magnetic field, and a 25T external magnetic field depresses the N-Ntb phase transition temperature by almost 1 degree C. We propose a quantitative mechanism to account for this shift and suggest a Helfrich-Hurault-type mechanism for the optical stripe formation.

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P. K. Challa, V. Borshch, O. Parri, C. T. Imrie, S. N. Sprunt, J. T. Gleeson, O. D. Lavrentovich, A. Jakli. 2014-07-31. Twist-bend nematic liquid crystals in high magnetic fields. https://doi.org/10.1103/physreve.89.060501

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