Local polarization and valence distribution in LaNiO3/LaMnO3 heterostructures

Abstract

The inside of the electrical double layer at perovskite oxide heterointerfaces is examined. Here, we report the local polarization and valence distribution in LaNiO${}_3$/LaMnO${}_3$ and LaMnO${}_3$/LaNiO${}_3$ bilayers on a SrTiO${}_3$ (001) substrate. Simultaneous measurements of two aspects of the structure are realized by using Bayesian inference based on resonant- and nonresonant-surface X-ray diffraction data. The results show that the average Mn valences are Mn${}^{3.12+}$ and Mn${}^{3.19+}$ for the two samples. The intensity of their local electric field is $\sim$1~GV/m and the direction of the field points from LaMnO${}_3$ to LaNiO${}_3$.

19pages, 4 figures