Cesium accumulation at CsB3O5 optical surface

Abstract Structure and element composition of polished CsB 3 O 5 surface have been studied. It has been shown that crystal surface is covered by thick layer (>50 A) of amorphous phase. This surface compound contains Cs, B and O and contaminated by hydrocarbons adsorbed on the surface. Element depth profiling produced by ion sputtering reveals quick and monotonic drop of C signal accompanied by increases of B and O signals with stabilization at depths higher than ∼20 A. The distribution of Cs over depth is irregular, top surface cesium content is ∼30% higher then that achieved for higher sputtering times. Being removed by sputtering, this top surface layer enriched by Cs is restored by few hours keeping at 24 °C in vacuum or air.