Quantitative light element analysis: Complementary IBA methods for H to O detection using an external proton beam

Abstract

A new setup for quantitative light element analysis of thin films using a 2.50–2.72 MeV external proton beam under atmospheric conditions is described. This setup simultaneously performs backscattering spectrometry (BS) and p-p coincidence elastic recoil detection analysis (C-ERDA) in transmission. BS utilizes a highly non-Rutherford cross-section for profiling of e.g. C, N and O whereas C-ERDA is used to measure H concentration profiles in foils of up to 12.5 μm in thickness. To validate the method, thin Ti layers are deposited on 200 nm Si3N4 membranes and loaded with H. The method shows an expected increase of H concentration in the films with longer loading times. Nuclear reaction analysis (NRA) for Li detection in LiMn2O4 samples is undertaken to test the possibility of using complementary proton scattering techniques simultaneously. A Li depth resolution of around 250 nm can be achieved. Radiation damage to Mylar and Kapton films is investigated and the radiation resistance of Kapton demonstrated.