Weighing at low gas pressures is a technique which is highly susceptible to temperature inhomogeneities. These temperature inhomogeneities cause spurious mass changes, the effect being usually called the thermomolecular flow effect. In a former paper by Poulis, Pelupessy, Massen and Thomas these effects were explained in the low pressure region (below 10 mtorr) on the basis of transverse and longitudinal Knudsen forces, which are both related to the Knudsen pressure difference, which at low pressures accompanies a temperature inhomogeneity. Though in nature a low pressure effect, the thermomolecular flow effect appears to be present at pressures as high as 100 torr. In the present paper the theory, originally set up for the low pressure region, is extended to higher pressures. Here, laminar gas flow can arise, accompanied by shearing forces, which have been allowed for in the theory. The theoretical results are compared with experimental data.

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A new nonvolatile memory with high density and high work-function metal nanodots, metal nanodot (MND) memory, was proposed and fundamental characteristics of MND capacitor were evaluated. In this work, a nanodot layer of FePt with high density and high work-function (∼5.2 eV) was fabricated as a charge storage site in nonvolatile memory, and its electrical characteristics were evaluated for the possibility of nonvolatile memory in view of cell operation by Fowler–Nordheim (FN) tunneling. Here, a nanodot FePt layer was controlled as a uniform single layer with dot size of under ∼2 nm and dot density of ∼1.2×1013/cm2. Electrical measurements of metal–oxide–semiconductor (MOS) structure with FePt nanodot layer shows a threshold voltage window of ∼6 V using FN programming and erasing, which is satisfactory for operation of the nonvolatile memory. Furthermore, this structure provides better data retention characteristics compared to other metal dot materials with similar dot density in our experiments. From these results, it is expected that this nonvolatile memory using an FePt nanodot layer with high dot density and high work-function can be a candidate structure for the future nonvolatile memory.