Uniform textures of smectic liquid-crystal phase formed by bent-core molecules

Smectic liquid crystals consisting of achiral bent-core molecules may be polar due to asymmetric packing of the molecules. Recently it was proposed that the planes of the molecules are tilted with respect to the smectic layers and the structure is chiral. The ground state is antiferroelectric and the majority of the films are racemic with the same tilt direction in the subsequent layers. Basically the tilt directions ate equivalent, and stripes with oppositely tilted molecules exist. In this paper we show that it is possible to suppress the formation of the stripes, and to obtain a uniform texture in thin films. In uniform racemic textures; weak quadratic electrooptical switching can be observed. Voltage dependences of the switching are measured and the switching mechanisms are discussed.