Optical and Piezoelectric Study of KNN Solid Solutions Co-Doped with La-Mn and Eu-Fe.

The solid-state method was used to synthesize single phase potassium-sodium niobate (KNN) co-doped with the La-Mn and Eu-Fe ion pairs. Structural determination of all studied solid solutions was accomplished by XRD and Rietveld refinement method. Electron paramagnetic resonance (EPR) studies were performed to determine the oxidation state of paramagnetic centers.