X-ray absorption spectroscopy characterization of embedded and extracted nano-oxides

The chemistries and structures of both embedded and extracted Y[sbnd]Ti[sbnd]O nanometer-scale oxides in a nanostructured ferritic alloy (NFA) were probed by x-ray absorption spectroscopy (XAS). Y₂Ti₂O₇is the primary embedded phase, while the slightly larger extracted oxides are primarily Y₂TiO₅. Analysis of the embedded nano-oxides is difficult partly due to the multiple Ti environments associated with different oxides and those still residing in matrix lattice sites. Thus, bulk extraction followed by selective filtration was used to isolate the larger Y₂TiO₅oxides for XAS, while the smaller predominant embedded phase Y₂Ti₂O₇oxides passed through the filters and were analyzed using the log-ratio method.