Quantification of dopant concentrations in dilute magnetic semiconductors using ion beam techniques

It has recently been demonstrated that magnetically doped TiO₂ and SnO₂ show ferromagnetism at room temperature and Curie temperatures above room temperature. However, accurate knowledge of dopant concentrations is necessary to quantify magnetic moments in these materials. Rutherford backscattering spectrometry (RBS) is one of the powerful techniques to quantify magnetic transition-metal dopant concentrations in these materials. However, in some cases, the interference of RBS signals for different dopants and substrate elements in these materials makes analysis difficult. In this work, we demonstrate that particle induced X-ray emission (PIXE) can be successfully used to quantify the magnetic transition-element dopants in several room temperature ferromagnetic materials synthesized using three different synthesis methods: oxygen plasma-assisted molecular-beam epitaxy, ion implantation and wet chemical synthesis.