银在不同波长下的折射率与介电常数数据精选.pdfVIP

350 David W. Lynch and W. R. Hunter Xl SILVER (Ag) From among the many studies of the optical properties of Ag [1-36], four have been chosen as representative. They are (1) the data of Hagemann et al. [28] from approximately 1.5 to 460 A, (2) the data of Leveque et al. [35] from 460 to 3600/I., (3) the data of Winsemius et al. [33] from 3600 A to 2.07 #m, and (4) the data of Dold and Mecke [14] from 1.265 to 10 #m. Table IX lists the values of n and k and the pertinent references. These data are plotted in Fig. 9 as smooth curves. Hagemann et al. [28] prepared their samples by evaporating thin films of silver onto substrates of collodion that were supported on copper screens of the type used for electron microscopy. The evaporation was done from resis- tance heated boats at a pressure of about 5 x 10 - 7 torr at rates of 10- 50 A/sec. The plastic substrates were dissolved away, leaving Ag films on copper screens. These processes required exposing the Ag films to air before measurements. Transmission measurements were made from 13 to 150 eV to obtain an absorption spectrum that was extended by using the data of others [10, 15, 22, 24, 26] to provide an absorption spectrum large enough for a Kramers-Kronig analysis. Leveque et al. [35] prepared their samples by the evaporation of silver in a vacuum of about 10- 7 torr. Reflectance measurements were made in the same chamber, and so there was no exposure to air. A variety of substrates was used, but for the data reported, the substrates wer