Determination of the doping profile of lanthanum impurities in thin-film barium titanate structures

The paper presents a calculation of doping concentration profile in a two-layer barium titanate film, one of the layers of which contains lanthanum impurity. The theoretically predicted distributions were experimentally verified. Influence of the doping profile on the magnitude of the electrocaloric (EC) response of ferroelectric films is assessed by numerical simulation. It is demonstrated that at the same La concentration, the magnitude of the EC effect can change by 40% due to the distribution of the lanthanum concentration in the structure. The results obtained allow optimizing the technological process to ensure the required characteristics of ferroelectric thin films.