Ising wall instability in a nematic liquid crystal

A new instability for a splay-bend Ising wall was found in a 5CB nematic li quid crystal layer. This instability, which occurs in the presence of an ex ternal horizontal magnetic field, is driven by the elastic anisotropy of th e liquid crystal material. Depending on the homogeneity of the magnetic fie ld, the unstable straight interface evolves towards a new steady state or u ndergoes a spinodal decomposition into facets. Energy arguments are given i n order to explain these physical phenomena.