BOOJUMS AND THE SHAPES OF DOMAINS IN MONOLAYER FILMS

Domains in certain Langmuir monolayers support a texture that is the t wo-dimensional version of the feature known as a boojum. Such a textur e has a quantifiable effect on the shape of the domain with which it i s associated. The most noticeable consequence is a cusplike feature on the domain boundary. We report the results of an experimental and the oretical investigation of the shape of a domain in a Langmuir monolaye r. A further aspect of the investigation is the study of the shape of a ''bubble'' of gaslike phase in such a monolayer. This structure supp orts a texture having the form of an inverse boojum. The distortion of a bubble resulting from this texture is also studied. The corresponde nce between theory and experiment, while not perfect, indicates that a qualitative understanding of the relationship between textures and do main shapes has been achieved.