Fig 14. Relationship between correlation lengths, plotted here as persistence length (κ /Lo) versus the defect density, normalized per unit period squared.
Based on data for a variety of annealed, neat and blended, cylinder-forming, PS-b-P2VP polymer thin films of a variety of molecular weights including blends, using images of the metallized P2VP domains on Si substrates. This enables direct comparison between different polymers, which result in patterns with different periodicities. Defects initially show a dramatic decrease, as structures move away from dot arrays, for which the normalized, defect metric would be ~1. Inset displays four representative images. Respectively, their periods are 32, 43, 36, & 37 nm; their correlation lengths are 19, 43, 65, & 121 nm; their defect densities are 744, 195, 134, & 42 defect pairs·μm-2.