TY - JOUR
T1 - Complex Fluorine Chemical Potential Effects on the Shape and Compositional Heterogeneity of KTa1- xNb xO3Nanoparticles
AU - Ly, Tiffany
AU - Wen, Jianguo
AU - Marks, Laurence D.
N1 - Funding Information:
This work was supported by the National Science Foundation (NSF) under grant no. DMR-1507101. Use of the Center for Nanoscale Materials, an Office of Science User Facility, was supported by the United States Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02-06CH11357. We thank K. R. Poeppelmeier for use of his hydrothermal synthesis laboratory equipment, and C. A. Mizzi for his assistance with X-ray photoelectron spectroscopy.
Publisher Copyright:
© 2020 ACS. All rights reserved.
PY - 2020/11/25
Y1 - 2020/11/25
N2 - When kinetic conditions dominate and dictate the growth in a nanoparticle synthesis, properties of the synthesis environment can have considerable effects on the properties of the products. Such effects were studied here, where the solution environment was changed via the addition of KF to the hydrothermal syntheses of KTa1-xNbxO3 and KTaO3. One result demonstrated the straightforward cause-and-effect relationship between the solution and reaction kinetics: KF directly increased the solution stability of the Ta species and therefore decreased its reaction rate, resulting in a change in composition heterogeneity of Ta and Nb in the KTa1-xNbxO3 particles. However, not all effects are so simple; changing the chemical potential of the solution with KF can also promote the formation of particles with anisotropic defect enhanced kinetic Wulff shapes instead of cuboidal shapes. The increased F chemical potential in the solution enabled the formation of planar defects in the bulk, which accelerated growth in-plane to form particles characterized by flat rectangular flake geometries. Thermodynamic modeling with density functional theory calculations confirmed that sufficient KF concentrations can drive the formation of a defect phase Kn+1TanO3nF.
AB - When kinetic conditions dominate and dictate the growth in a nanoparticle synthesis, properties of the synthesis environment can have considerable effects on the properties of the products. Such effects were studied here, where the solution environment was changed via the addition of KF to the hydrothermal syntheses of KTa1-xNbxO3 and KTaO3. One result demonstrated the straightforward cause-and-effect relationship between the solution and reaction kinetics: KF directly increased the solution stability of the Ta species and therefore decreased its reaction rate, resulting in a change in composition heterogeneity of Ta and Nb in the KTa1-xNbxO3 particles. However, not all effects are so simple; changing the chemical potential of the solution with KF can also promote the formation of particles with anisotropic defect enhanced kinetic Wulff shapes instead of cuboidal shapes. The increased F chemical potential in the solution enabled the formation of planar defects in the bulk, which accelerated growth in-plane to form particles characterized by flat rectangular flake geometries. Thermodynamic modeling with density functional theory calculations confirmed that sufficient KF concentrations can drive the formation of a defect phase Kn+1TanO3nF.
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U2 - 10.1021/acs.jpcc.0c07517
DO - 10.1021/acs.jpcc.0c07517
M3 - Article
AN - SCOPUS:85096537179
SN - 1932-7447
VL - 124
SP - 26012
EP - 26017
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 47
ER -