Abstract
This work investigates the role of crystallization layers’ periodicity and thickness on functional response in chemical solution-deposited lead zirconate titanate thin films, with periodic, alternating Zr and Ti gradients normal to the surface of the film. The films were processed with a range of layer periodicities and similar total film thickness, in order to relate the number of layers and compositional oscillations to structural and functional response changes. Trends of increased extrinsic contributions to the dielectric and ferroelectric responses are observed with increasing layer periodicity, but are counterpointed by simultaneous reduction in intrinsic contributions to the same. Transmission electron microscopy reveals in-plane crystallographic discontinuity at individual crystallization interfaces. Samples with smaller periodicity, and thus thinner layers, potentially suffer from grain size refinement and subsequent reduction in domain size, thereby limiting extrinsic contributions to the response. The strong compositional oscillations in samples with larger periodicity result in deep fluctuations to the tetragonal side of the phase diagram, potentially reducing intrinsic contributions to the response. Conversely, piezoresponse force microscopy results suggest that large chemical oscillations in samples with larger periodicity also result in closer proximity to the morphotropic phase boundary, as evidenced by local acoustic softening at switching, signaling potential field-induced phase transitions.
Original language | English |
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Pages (from-to) | 5561-5572 |
Number of pages | 12 |
Journal | Journal of the American Ceramic Society |
Volume | 100 |
Issue number | 12 |
DOIs | |
State | Published - Dec 2017 |
Externally published | Yes |
Funding
S.B., S.W., C.D., and N.B.G. acknowledge funding from the U.S. National Science Foundation (NSF) under grant numbers DMR-1255379 and CMMI-153726.2. S.B. and N.B.G acknowledge. support by the Defense Threat Reduction Agency, Basic Research Award No. HDTRA1-15-1-0035 to Georgia Institute of Technology. The contents do not necessarily reflect the position or the policy of the federal government, and no official endorsement should be inferred. A.B.N. and A.K. acknowledge support by Department of Education and Learning, Northern Ireland through the US-Ireland R&D partnership grant no. USI-082 and funding support from the Engineering and Physical Sciences Research Council (EPSRC) through contract EP/ N018389/01. S.M. N. and B.J.R. acknowledge support from Science Foundation Ireland (14/US/I3113). A portion of this research was conducted at the Center for Nanophase Materials Science which is a DOE Office of Science User Facility, under proposal number CNMS2014-282. The authors gratefully acknowledge Ronald G. Polcawich and Joel Martin of the U.S. Army Research Laboratory for providing the platinized Si substrates for this work. Department of Energy Office of Science User Facility, Center for Nanophase Materials Science, Grant/Award Number: CNMS2014-282; Defense Threat Reduction Agency, Basic Research Grant/ Award Number: HDTRA1-15-1-0035; National Science Foundation (NSF), Grant/Award Number: DMR-1255379, CMMI-153726.2; Department of Education and Learning, Northern Ireland, Grant/Award Number: USI-082; Engineering and Physical Sciences Research Council, Grant/Award Number: EP/N018389/01; Science Foundation Ireland, Grant/Award Number: 14/US/ I3113
Keywords
- dielectric materials/properties
- ferroelastic materials
- ferroelectricity/ferroelectric materials
- lead zirconate titanate
- piezoelectric materials/properties