Measurement of X-ray absorption spectra (XAS) of insulators by the partial electron yield method using an electron flood gun

X-ray absorption spectra (XAS) of bulk insulator samples were successfully obtained by using the partial electron yield method, which involves a low-energy flood gun, floating Ar ion gun, and an electron detector. The low-energy flood gun and floating Ar ion gun are used to avoid charging of the insulator surface during the measurement. A retarding mesh located in front of the electron detector was used to reject the law-energy electrons scattered by the sample surface. For two polymer samples (polytetrafluoroethylene film and polyimide film) and one insulating ceramic disk (hexagonal boron-nitride), the optimal operating conditions for the electron flood gun, Ar ion gun, and retarding voltage were sample-dependent. (C) 2001 Elsevier Science BN. All rights reserved.