Abstract
Relaxor ferroelectrics exemplify a class of functional materials where interplay between disorder and phase instability results in inhomogeneous nanoregions. Although known for about 30 years, there is no definitive explanation for polar nanoregions (PNRs). Here we show that ferroelectric phonon localization drives PNRs in relaxor ferroelectric PMN-30%PT using neutron scattering. At the frequency of a preexisting resonance mode, nanoregions of standing ferroelectric phonons develop with a coherence length equal to one wavelength and the PNR size. Anderson localization of ferroelectric phonons by resonance modes explains our observations and, with nonlinear slowing, the PNRs and relaxor properties. Phonon localization at additional resonances near the zone edges explains competing antiferroelectric distortions known to occur at the zone edges. Our results indicate the size and shape of PNRs that are not dictated by complex structural details, as commonly assumed, but by phonon resonance wave vectors. This discovery could guide the design of next generation relaxor ferroelectrics.
| Original language | English |
|---|---|
| Article number | 3683 |
| Pages (from-to) | 3683 |
| Number of pages | 1 |
| Journal | Nature Communications |
| Volume | 5 |
| DOIs | |
| State | Published - 2014 |
Funding
Research was sponsored by the US Department of Energy, Office of Basic Energy Sciences, Materials Sciences and Engineering Division. We acknowledge the support of the National Institute of Standards and Technology, US Department of Commerce, in providing the neutron research facilities used in this work. The identification of any commercial product or trade name does not imply endorsement or recommendation by the National Institute of Standards and Technology. The portion of this research performed at the Oak Ridge National Laboratory’s Spallation Neutron Source was sponsored by the US Department of Energy, Office of Basic Energy Sciences. We acknowledge discussions with Takeshi Egami, Sergey Vakhrushev and Alexander Taganstev. We also thank Judy Pang, Ben Larson and Chen Li for proof reading the manuscript.
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | |
| National Institute of Standards and Technology | |
| U.S. Department of Commerce | |
| Basic Energy Sciences | |
| Oak Ridge National Laboratory | |
| Division of Materials Sciences and Engineering |