Intrinsic stress has been investigated id thin nickel films which were vapor deposited in ultrahigh vacuum (UNV) on nickel substrates. The cantilevered beam technique was used for measuring the film force per unit width as a funCtiOIl of film thickness. A ney method, based on Single Slit diffraction, was developed for observing the substrate deflection. The stresses were tensile, and the average values d.ecreased 9 from 9.3 x 10 dynes/cm2 with 5.4 at.% impurities, to 4.2 x .10 1 dynes/cm with 10.1 at.% impurities. The film impurity concentra-• tions, determined from Auger electron spectroscop y depth profile data, showed a similar correlation with the instantaneou s stresses, as a function of film thickness. The source of the impurities was determined to be the evaporation filament. The films, 41,000 R thick, were examined with electron microscopy , and were found to be polycryst alline, with B100-150 9 grain diameters. A study was made of the residual gas characteris tics of Ull\/ under various conditions, DISTR•IBU' TION OF THIS DOCUMEN T ;S UNLIMITEQ M DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency Thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. ' and methane was found to be the predominant gas of the.baked UHV. The results are interpreted in terms of the grain boundary model, which is presented in an interfacial energy formulation. The stress depends on free surface and grain boundary energies which I are reduced by impurity concentrations, and oxygen is believed to play the most active role. The model is qualitatively consistent I with the experimental results. This report was prepared as an account of Government-sp onsored work. Neither the United States, nor the Atomic Energy Commission, nor any person acting on behalf of the Commission: A. Makes any warranty or representation , expressed or implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any I information, apparatus, method, or process disclosed in this report may not infringe privately owned rights; or ' B. Assumes any liabilities with respect to the use of, or for damages resulting from the use of, any information, apparatus, method, or process disclosed in this report. As used in the above, "pers...