Recently, A paper named " Atomic Resolution Interfacial Structure of Lead-free Ferroelectric K0.5Na0.5NbO3 Thin films Deposited on SrTiO3 " is published in Scientific Reports (IF:5.228). Mr. Chao Li is the first.
Oxide interface engineering has attracted considerable attention since the discovery of its exotic properties induced by lattice strain, dislocation and composition change at the interface. In this paper, the atomic resolution structure and composition of the interface between the lead-free piezoelectric (K0.5Na0.5)NbO3 (KNN) thin films and single-crystalline SrTiO3 substrate were investigated by means of scanning transmission electron microscopy (STEM) combining with electron energy loss spectroscopy (EELS). A sharp epitaxial interface was observed to be a monolayer composed of Nb and Ti cations with a ratio of 3/1. The First-Principles Calculations indicated the interface monolayer showed different electronic structure and played the vital role in the asymmetric charge distribution of KNN thin films near the interface. We also observed the gradual relaxation process for the relatively large lattice strains near the KNN/STO interface, which remarks a good structure modulation behavior of KNN thin films via strain engineering.
The authors acknowledge the fundings from the National Natural Science Foundation of China (51202180, 51202184 and 51332003), the 111 project of China (B14040), the Fundamental Research Funds for the Central Universities in China, the Guangxi Science Foundation (2013GXNSFFA019001) and the Guangxi Key Laboratory Foundation (15-140-54).
Link:http://www.nature.com/articles/srep37788
