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A simple technique has been developed for the high resolution measurement of small changes in capacitors which have one grounded electrode. The capacitor is arranged to be the tuning element in a series resonant LC tank circuit that is driven by a transistor emitter follower. Signal information is provided by observing the phase shift in the transistor collector current that results from any small change in the capacitor value. Implementation is simple, readily analyzable, provides good diagnostics, is easily multiplexed into arrays, and has potential applications in a number of areas including high resolution proximity sensing, capacitive topography, atomic force microscopy, and capacitor microphones.

A wide variety of experiments in semiconductor physics involve the observation of a particular class of time‐dependent transient signals; namely, decaying exponentials. Such signals are characteristic of systems relaxing back to equilibrium following an abrupt change in the populations of carriers occupying the available states. The magnitudes of such signals indicate the density of states involved, while the decay time constants (as a function of temperature) provide information on the energy level of the states in question. As such, both the amplitudes and the time constants of such signals are of physical interest. The problem of processing such signals has been examined using the theory of linear filtering and as a result a special purpose signal processor has been developed. This processor performs a continuous real‐time cross correlation between the experimental signals and an appropriately synchronized locally generated exponential waveform. The resulting system has been used to process signals fro...

A new pulsed nonlinearity measurement is described and applied to the characterization of thin‐film conductor stripes. The method is based on the phenomenon of ’’baseline shift’’, and is substantially simpler than the already familiar third‐harmonic method yet, at least potentially, just as sensitive. A model is proposed in which the observed nonlinearity is attributed to the temperature rise accompanying current in conductors and the associated resistance change. Good quantitative agreement has been obtained with predictions based on the model. A specific application of this method to reliability testing has been found in magnetic bubble memories, the lifetime of which correlated closely with pulse nonlinearity measurements.

Using the magneto‐optical Kerr effect, it is shown that the surface magnetization and the bulk magnetization of both polycrystalline and single‐crystal iron plates behave quite differently. In particular, a distinctive ’’lag’’ is observed in the surface magnetization, except when the single crystal is magnetized along the easy 〈100〉 direction. The surface magnetization of the single crystal is highly anisotropic. Implantation of a dose of 1015 Fe+ ions/cm2 into a polycrystalline plate causes a change in the shape of the magnetization curve.

Electrolytic lithium doping of high‐purity polycrystalline silicon samples has been shown to increase not only the material conductivity but also the minority‐carrier lifetime.