For SE analysis, an optical model of our samples is firstly constructed, which consists of a semi-infinite Si substrate/pure ZnO or AZO film/air ambient structure.
It is supposed that these constants reflect the ambient structure as the experimental situation is modified, and might be calculable with regard to a more fundamental theory.
The dielectric functions of SRO were extracted by minimizing the RMSE value to fit the ellipsometric data of the SRO buffer layer to a three-medium optical model consisting of a semi-infinite STO substrate/SRO film/air ambient structure.
The refractive index of Al2O3 thin films was described by Cauchy model and the ellipsometric spectra data were fitted to a five-medium model consisting of Si substrate/SiO2 layer/surfaceayeroughness/airghness/ambientient structure.
The dielectric functions of STO, SRO, and BFO are obtained by fitting their spectra data to different models in which BFO corresponds to a five-medium optical model consisting of a semi-infinite STO substrate/SRO film/BFO film/surface roughness/air ambient structure.
Following the dielectric functions of STO and SRO, the ones of BFO described by the Lorentz model are received by fitting the spectra data to a five-medium optical model consisting of a semi-infinite STO substrate/SRO layer/BFO film/surface roughness/air ambient structure.
The inset of Figure 1 sketches a five-medium optical model consisting of a semi-infinite STO substrate/SRO layer/BFO film/surface roughness/air ambient structure employed to investigate the BFO thin film where the roughness layer is employed to simulate the effect of surface roughness of the BFO film on SE measurement.
Each unit cell contains 96 tetrahedral units and the hexagonal unit-cell parameters of the ambient structure are a, b = 17.37, c = 28.36 Å.
The ambient pressure structure has been reported previously; 7a however, revisiting significant structural details is important to understand the interesting behavior.
successfully determine the ambient pressure structure of lithium metatitanate, they cannot be used at non ambient conditions like high pressure [1].
