An x-ray source can have increased x-ray flux and can simultaneously provide characteristic peaks and from multiple, different chemical elements. The target can include multiple layers of different chemical compositions. These layers can be distinguished by a higher atomic number, a higher energy K-alpha x-ray characteristic line, and a higher density in one layer compared to another layer. The layer that is lower in these characteristics can face the x-ray window. The layers can be formed by sputter deposition.