Abstract
Relaxor ferroelectrics are important in technological applications due to strong electromechanical response, energy storage capacity, electrocaloric effect, and pyroelectric energy conversion properties. Current efforts to discover and design materials in this class generally rely on substitutional doping as slight changes to local compositional order can significantly affect the Curie temperature, morphotropic phase boundary, and electromechanical responses. In this work, we demonstrate that moving to the strong limit of compositional complexity in an ABO3 perovskite allows stabilization of relaxor responses that do not rely on a single narrow phase transition region. Entropy-assisted synthesis approaches are utilized to synthesize single-crystal Ba(Ti0.2Sn0.2Zr0.2Hf0.2Nb0.2)O3 [Ba(5B)O] films. The high levels of configurational disorder present in this system are found to influence dielectric relaxation, phase transitions, nanopolar domain formation, and Curie temperature. Temperature-dependent dielectric, Raman spectroscopy, and second-harmonic generation measurements reveal multiple phase transitions, a high Curie temperature of 570 K, and the relaxor ferroelectric nature of Ba(5B)O films. The first-principles theory calculations are used to predict possible combinations of cations to design relaxor ferroelectrics and quantify the relative feasibility of synthesizing these highly disordered single-phase perovskite systems. The ability to stabilize single-phase perovskites with various cations on the B-sites offers possibilities for designing high-performance relaxor ferroelectric materials for piezoelectric, pyroelectric, and electrocaloric applications.
Original language | English |
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Pages (from-to) | 11962-11970 |
Number of pages | 9 |
Journal | ACS Applied Materials and Interfaces |
Volume | 14 |
Issue number | 9 |
DOIs | |
State | Published - Mar 9 2022 |
Funding
This work was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), Materials Sciences and Engineering Division (conception, synthesis, structural characterization, and theory). Optical characterization performed at Los Alamos National Laboratory was supported by the G. T. Seaborg Institute under project number 20210527CR, and NNSA’s Laboratory Directed Research and Development Program and was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the U.S. Department of Energy’s NNSA, under contract 89233218CNA000001. Some microscopy measurements were conducted through user proposal at the Center for Nanophase Materials Sciences, which is a US DOE, Office of Science User Facility. K.K.M. and R.S.K. acknowledge financial support from the Department of Defense, USA (DoD grant #FA9550-20-1-0064). This work was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences (BES), Materials Sciences and Engineering Division (conception, synthesis, structural characterization, and theory). Optical characterization performed at Los Alamos National Laboratory was supported by the G. T. Seaborg Institute under project number 20210527CR, and NNSA?s Laboratory Directed Research and Development Program and was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. Department of Energy Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the U.S. Department of Energy?s NNSA, under contract 89233218CNA000001. Some microscopy measurements were conducted through user proposal at the Center for Nanophase Materials Sciences, which is a US DOE, Office of Science User Facility. K.K.M. and R.S.K. acknowledge financial support from the Department of Defense, USA (DoD grant #FA9550-20-1-0064).
Keywords
- configurational disorder
- dielectrics
- high entropy oxides
- perovskite oxides
- relaxor ferroelectrics
- thin film epitaxy