Infrared Reflectance and Emittance of Silver and Gold Evaporated in Ultrahigh Vacuum

Jean M. Bennett, E. J. Ashley
1965 Applied Optics  
The reflectance of silver and gold evaporated in ultrahigh vacuum has been measured in the wavelength range from 0.5 U to 32 u. It was found that the reflectance of both materials is higher than previously reported values, and that ultrahigh vacuum silver films have the highest infrared reflectance over an extended wavelength range of any known material. The infrared emittance of uhv gold films is nearly as low as that of silver and is smaller by nearly a factor of 3 than the value previously
more » ... value previously reported for this material. Since gold is chemically inert and its emittance apparently does not change with time, it should find wider application as a low infrared emittance material, particularly in problems involving radiative heat transfer. . «tflfUd mu..t.r. «7 obtain copi.s of thl. roport dlroot f*. ST. FOREWORD This report discusses the reflectance and emittance of silver and gold films evaporated in ultrahigh vacuum. The measurements were made with high precision at normal incidence in the 0.5 to 32 y wavelength region. Both materials have a higher reflectance than has previously been reported and ultrahigh vacuum silver films have the highest infrared reflectance over an extended wavelength range of any known material. The reflectance of silver and gold evaporated in ultrahigh vacuum has been measured in the wavelength range from 0.5 »to 32 *. It wae found that the reflectance of both materiah ia higher than previously reported values, and that ultrahigh vacuum silver films have the highest infrared reflectance over an extended wavelength range of any known material The infrared emittance of uhv gold films is nearly as low as that of silver and to smaller by nearly a factor of 3 than the value previously reported for this material. Since gold is chemically inert and its emittance apparently does not change with time, it should find wider application as a low infrared emittance material, particularly in problems involving radiative heat transfer.
doi:10.1364/ao.4.000221 fatcat:hso7r6wdgnga5kch63wkrmfra4