| Resonant soft x-ray reflectivity (RSoXR), a new method for the study of soft condensed matter materials that combines aspects of neutron reflectivity and x-ray reflectivity, is developed. RSoXR utilized the complex index of refraction, n = 1 - delta + ibeta, of organic materials that varies rapidly as a function of photon energy near the absorption edge in a manner that strongly depends on the chemical moieties and functionalities present in the material. By tuning the photon energy, the contrast at and the sensitivity to certain interface can be greatly enhanced. This near edge contrast enhancement mimics the specific contrast achieved through deuterium labeling in neutron reflectivity (NR) yet does not require any chemical modification. The capabilities of RSoXR are exemplified using a number of polymeric bi- and multilayers. Furthermore, different applications of RSoXR has been explored, which includes the study of index of refraction for polymers near absorption edge, the effect of isotopic labeling on polymer/polymer interface, and the interfacial structure of multilayer PLED devices and its correlation with the device performance. |
