B-K in metallic Co0.4Fe0.2B0.2 has an edge onset at 188 eV. The step-function-like shape of the edge reflects its metallic, almost free-electron-like DOS. This edge can be difficult to detect in thick samples due to plural scattering from valence excitations
By: Judy Cha @ Cornell University
Microscope: FEI Tecnai T20
Note: Composition of the material is: Co40%Fe20%B20%