Atomic force microscope (AFM) is now a standard imaging tool in laboratories but has displayed limited capability of nanolithography. We discover that an internal tensile strain exists in poly(3-hexylthiophene-2,5-diyl) (P3HT) films, and the physical effect is utilized to achieve highly tunable and high-throughput nanolithography. Trenches with widths spanning nearly two orders of magnitude from 40nmto2.3μm are fabricated. We show that P3HT is also excellent for pattern transfer to inorganic materials. Furthermore, a lithography speed of 0.5mm∕s is achieved, which is a few orders of magnitude higher than other known methods of AFM-based nanolithography.

An alternative approach is proposed for the analysis of optical isotope shifts. It is shown that for many elements a plot of the shift for one isotope pair against that for another pair for a series of transitions is linear. In certain circumstances the gradient of this plot gives the ratio of the change in mean square charge radii of the isotope pairs directly. Alternatively the plot is helpful in making judgements as to whether specific mass effects are likely to be negligible, with the field shift dominant, and hence assisting other methods of analysis. The possible range of validity is discussed.

A new phenomenon in electroformed metal‐insulator‐metal thin film devices is studied. Devices biased in a particular voltage range undergo a reverse negative differential resistance (NDR) change whereby the device resistance decreases exponentially over a period of several minutes. The effect occurs for both SiOx and MgF2 devices but the behaviour is dependent upon the particular metal electrodes used andthe polarity of non‐symmetrical devices. The conductivity is decreased in the presence of either oxygen or argon. The reverse‐NDR effectis interpreted in terms of reforming by ionic diffusion and is in accordance with a forming/conduction model based on conducting filaments locatedaround dielectric breakdown pinholes.