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Experimental results on the temperature dependence of the internal voltage in aluminum/(alumina) ‐barium‐stearate/tin sandwich structure have been described in the temperature range 50–0 °C. It is observed that the internal voltage, which arises from the asymmetric nature of the electrodes and due to the dipole field in the alumina film, decreases with decrease of temperature. The observed temperature dependence of the internal voltage has been attributed mainly to the thermal excitation of impurities in the insulating alumina film.

Work functions of some metals (Mg, Mn, Cr, Bi, Cd, Pb, Te, Zn, and Sn) have been determined by using the zero‐bias internal‐voltage technique in asymmetric electrodes structures of metal/insulator/metal systems. The built‐up Langmuir films of barium‐stearate have been used as an insulator in these structures, as the thicknesses of the multilayer Langmuir films are known accurately and the effect of the thickness dependence of the internal voltage can be corrected for when obtaining a work function from internal‐voltage measurements. Any contribution arising due to alumina (Al2O3) film on base aluminum electrodes has also been accounted for, to give the correct value of the work function. The measured values of the work function by this technique are found to be in agreement with the known data.

Studies and measurements of internal voltage in a metal‐insulator‐metal structure with similar electrodes, when the insulator molecules have dipole moments all oriented parallel to each other, have been reported here. The measured voltage has been shown to be directly related to the dipole moment of the carboxylic group in the barium‐stearate molecule. The work reported provides a method of measuring the dipole moment of suitably orientable molecules. The transient behavior of the currents at zero bias through the above system has also been studied.

It has been shown that internal voltage in metal/insulator/metal structures can be used successfully to measure the electric dipole moment of organic compounds which can be built up in the form of monomolecular layers. Using this technique the dipole moment of stearic acid has been determined and compared with the known data for this fatty acid, and the agreement has been found to be good.

It has been shown that an internal voltage exists even in the case of symmetric metal/insulator/metal junctions with the insulating organic film having no net dipole moment. In the case of aluminum/barium‐stearate/aluminum junctions, this voltage arises due to the polar nature of the thin alumina (Al2O3) film which is formed on the bottom electrode of aluminum during its exposure to the atmosphere, prior to the deposition of barium‐stearate film.

The present work reports a detailed experimental investigation of Schopper's formula for investigating the case of a uniaxial nonabsorbing film of barium stearate on a transparent substrate. The required theoretical conditions for the experimental study of Schopper's formulas are well fulfilled for the film studied. The experimentally measured values of the reflectances and transmittances for Ba stearate films are found to be in agreement with the corresponding values calculated from the corrected Schopper's formulas. The experimental values, in general, are found to be in considerable disagreement with the corresponding values calculated by assuming the films to be isotropic. The studies have thus tested the validity of Schopper's formulas and have, indeed, confirmed the films to be anisotropic. Thus, assuming the validity of Schopper's formulas, the refractive indices of several other Blodgett‐Langmuir films have been determined.

The potential importance of built‐up films of barium stearate for making dielectric devices has led to the necessity of the study of their ac breakdown characteristics. In the present work, the thickness and frequency dependence of the ac breakdown field has been reported in the thickness range 100–1500 A and in the frequency region 10–200 kHz. The breakdown field is found to vary with thickness as d–a (α=0.68) and the breakdown voltage is found to increase with increasing thickness and frequency in the specified ranges. Although the experimental results could not be interpreted at present, the results obtained may prove useful in ac device applications of the films.