Perovskitemanganites of the formula R1-xAxMnO3 (R being a trivalent rare earth and A being a divalent alkaline-earth ion) have attracted great attention recently due to their wide variety of electronic, magnetic, and structural states, and the coexisted and competitive mechanisms associated with the strong coupling among the spin, charge and orbital degrees of freedom. These materials are sensitive to magnetic, electric fields, pressure, and X-ray/visible light irradiation.The charge- and orbital-ordered (CO/OO) state in perovskite manganites has aroused a lot of interest for its colossal response to external stimuli.
Ferroelectric thin films including BaTiO3, SrTiO3, and (Ba,Sr)TiO3(BSTO) have received great attention because of their potential applications for various functional devices. Extensive research work has indicated that the dielectric properties of epitaxial BSTO thin film strongly depend on internal stress and defect structure. For BSTO thin films grown on a single-crystalline substrate such as LaAlO3, there is a lattice mismatch (about 3.8%) and difference in their thermal coefficients. These differences lead to the formation of dislocations, stacking faults (SFs), and antiphase domains in the epitaxial film. These defects could increase the dielectric loss and reduce the tuneability of the film. Thus, it is necessary to carry out a comprehensive investigation of the defect structures in epitaxial BSTO films.
Key Publications:
[1]. Y. H. Ding, R. S. Cai, Y. Q. Wang, Y. Z. Chen, J. R. Sun, Dislocations in Bi0.4Ca0.6MnO3 epitaxial film grown on (110) SrTiO3 substrate, Materials Letters, 67(1), 67-69 (2012).
[2]. Y. Q. Wang, W. S. Liang, W. J. Kong, P. K. Petrov, N. M. Alford, Structural engineering of Ba0.5Sr0.5TiO3 epitaxial film, Thin Solid Films, 520(18), 5918-5921 (2012).
[3]. Li Chun-Yan，Liu Xue-Hua，Diao Fei-Yu, Liang Wen-Shuang, Wang Yi-Qian, Petrov Peter, Alford Neil, Microstructural defects and their formation mechanisms in Ba0.75Sr0.25TiO3 epitaxial film, Journal of Inorganic Materials, 27(3), 285-290 (2012).
[4]. Y. H. Ding, Y. Q. Wang, R. S. Cai, Y. Z. Chen, J. R. Sun, Charge ordering modulations in Bi0.4Ca0.6MnO3 film with a thickness of 110 nm, Chinese Physics B, 21(8), 087502 (2012).
[5]. Y. H. Ding, Y. Q. Wang, R. S. Cai, Y. Z. Chen, J. R. Sun, Effect of anisotropic strain on the charge ordering behavior in Bi0.4Ca0.6MnO3 films, Applied Physics Letters, 99(19), 191914 (2011).
[6]. Y. Q. Wang, W. S. Liang, P. K. Petrov, N. M. Alford, Antiphase boundaries in Ba0.75Sr0.25TiO3 epitaxial film grown on (001) LaAlO3 substrate, Applied Physics Letters, 98(9), 091910 (2011).
[7]. Y. H. Ding, R. S. Cai, Q. T. Du, Y. Q. Wang, Y. Z. Chen, J. R. Sun, Microstructure evolution of Bi0.4Ca0.6MnO3 epitaxial films with different thickness, Journal of Crystal Growth, 317(1), 115-118 (2011).
[8]. Y. Q. Wang, W. S. Liang, P. K. Petrov, N. M. Alford, Dissociation of misfit and threading dislocations in Ba0.75Sr0.25TiO3 epitaxial film, Materials Characterization, 62(3), 294-297 (2011).
