Commensurate defect superstructures in a Langmuir-Blodgett film

Molecular-resolution atomic force microscope images of Ba arachidate Langmuir-Blodgett multilayers show two previously unknown structures, a tilted (26^∘{}) triclinic packing with a 3×{}1 sawtooth height modulation, and a tilted (19^∘{}) rectangular herringbone packing with an alternating vertical offset, along with untilted disordered regions, all within the same molecular layer. The submicron extent of each region, the extent of twinning and defects, and the complexity of the molecular packing make the determination of the lattice structure of these materials impossible by any other technique.