Temperature-Modulated Reflectance of Gold from 6 to 35 eV

The thermoreflectance spectrum of gold has been measured in the 6-35-eV region at about 200 K by using synchrotron radiation. Considerable sharp structure exists throughout this region, showing that lifetime broadening is not large enough to preclude the extension of high-resolution modulation techniques to at least 35 eV. The structure arises from interband transitions of the $5d$ electrons and from plasmons.