Composition control and thickness dependence of {100}-oriented epitaxial BiCoO3–BiFeO3 films grown by metalorganic chemical vapor deposition

Abstract

Articles you may be interested inHigh symmetric SrRuO3 (001) thin films: Perfectly lattice-matched electrodes for multiferroic BiFeO3 J. Appl. Phys. 113, 17D913 (2013); 10.1063/1.4795864Multiferroic and structural properties of BiFeO3 close to the strain induced phase transition on different substrates Fabrication of ferroelectric SrBi 2 Ta 2 O 9 capacitor films using plasma-assisted metalorganic chemical vapor deposition and their electrical properties xBiCoO 3 -͑1−x͒BiFeO 3 films were deposited by metalorganic chemical vapor deposition. Although the film composition changed with deposition temperature, the composition could be adjusted by varying the input source gas composition at 700°C. Moreover, adjusting the deposition time could change 0.16BiCoO 3 -0.84BiFeO 3 film thickness. The crystal symmetry changed from rhombohedral to tetragonal as the film thickness decreased for 0.16BiCoO 3 -0.84BiFeO 3 films grown on both ͑100͒SrTiO 3 and ͑100͒ c SrRuO 3 ʈ ͑100͒SrTiO 3 substrates, implying that the x value of the crystal symmetry boundaries between the tetragonal and rhombohedral structures changes with film thickness.

Enhancement of phase stability and optoelectronic performance of BiFeO3thin filmsviacation co-substitution

“…It is obtained a remanent polarization of 53µC/cm 2 , similar to that obtained for epitaxial BFCO films and slightly higher than pristine BFO films. 21,60 Note that similar behavior is also identified in thicker (> 300 nm) (La)BFO polycrystalline films but at significantly lower Co dopings ( 2-3%). 61,62 Additionally, piezoelectric characterization has been performed in La-BFCO LSMO-buffered 20 nm films.…”

First-Principles Investigation of Morphotropic Transitions and Phase-Change Functional Responses inBiFeO3−BiCoO3Multiferroic Solid Solutions

“…The X-ray experiments of Azuma et al [7] confirmed that, as the Co content grows, BFCO moves from R to T traversing a narrow region of presumably monoclinic (M ) symmetry. (Similar results have been obtained for thin films [8].) This is reminiscent of what occurs in prototype piezoelectric PbZr 1−x Ti x O 3 (PZT), where the M phase found at the MPB [9] is characterized by its structural softness and large electromechanical responses [10].…”

Effect of Film Thickness and Crystal Orientation on the Constituent Phase in Epitaxial BiFeO3–BiCoO3 Films Grown on SrTiO3 Substrates

“…The crystal structure of the film was changed by film thickness. 17) The changes in XRD patterns with x value are shown in Figs. 1(a) and 1(b) for (1 À x)BiFeO 3 -xBiCoO 3 films of about 200 and 400 nm thickness, respectively, grown on (100)SrTiO 3 substrates.…”

“…unit) Two types of rhombohedral symmetries labeled R-1 and R-2 and their phase stability are already described elsewhere. 16,17) When the x value increased at a thickness below 200 nm, the crystal symmetry changed from rhombohedral to tetragonal symmetry through the mixture of these symmetries. Finally, it reached the region where the perovskite phase with tetragonal symmetry including impurities was obtained at a thickness above 200 nm.…”

“…13,14) For example, tetragonal BiCoO 3 and Bi(Zn 1=2 Ti 1=2 )O 3 were respectively synthesized under 6 GPa and 1243 K, and 6 GPa and 1173 K. 8,12) The phase boundary in the BiFeO 3 -BiCoO 3 solid solution system was firstly reported for epitaxial films grown on (100)SrTiO 3 and (100) c SrRuO 3 == (100)SrTiO 3 perovskite substrates by metalorganic chemical vapor deposition (MOCVD). [15][16][17] Such experiments demonstrated that the structural analysis of epitaxial thin films is effective for material survey in novel solid solution systems, such as BiMO 3 , which is usually synthesized only under a high pressure. However, the crystal structure of epitaxial films is generally affected by the substrates.…”