Amorphous carbon: how much of free hydrogen?

Abstract A method of stepped isochronous heating was used for investigation of the state and amount of free and bonded hydrogen in amorphous carbon (a-C:H) films. Hydrogen and other gas effusion processes were studied on unprotected and Pd layer protected a-C:H film which allow the separation of hydrogen from CnHm components. The amount of hydrogen released by the breaking of weak C H bonds was determined to be 10 at.%, and that released by the breaking of strong C H bonds was 12 at.%. The amount of free hydrogen in the material was estimated at 12–14 at.%.