Profiling of Fiber Texture Gradients by Anomalous X-ray Diffraction

Preferred crystallographic orientation or texture is a typically observed phenomenon in polycrystalline thin films. In addition, texture was revealed in numerous x-ray diffraction studies to increase with layer thickness. The phenomenon is rather significant for the optimized preparation of thin films, but was difficult to measure so far. A method is presented that allows for texture profiling by exploiting the anomalous variation of the x-ray attenuation coefficient in the vicinity of an elemental absorption edge. The study reports the application of the technique to thin ZnO:Al films by measuring with wavelengths below and above the Zn K edge. Large texture gradients between 0.03 and 0.3 mrd/nm were revealed to arise in these samples. Anomalous diffraction is concluded to enable the determination of texture gradients as required in many thin film projects.