A STUDY OF DEUTERIUM PERMEATION THROUGH THIN BN FILMS

Stainless steel membranes have been coated by using the ion beam assis ted deposition technique with BN thin films: some deposited films exhi bit the cubic microcrystalline structure (c-BN) while others exhibit t he hexagonal one (h-BN). The samples have been submitted to deuterium permeation tests and in a second step they have been analysed by elast ic recoil detection (ERD). It was observed that the permeation flux tr ansient is sensible to the structure of the deposited layers as sugges ted by the different shape of the permeation curves pertinent to the h -BN or to the c-BN coated samples. These different shapes have been at tributed to deuterium trapping processes in the BN layers with the hex agonal structure: the higher deuterium content in the h-BN than in the c-BN, after permeation, as revealed by ERD analysis, is consistent wi th the previous observation. (C) 1997 Elsevier Science S.A.