In situ X-ray and neutron diffraction studies of dielectric and piezoelectric materials. 2 θ. ω. Acquisition Electronics. Function Generator. Amplifier or HV switch. PC. (00 h ). cubic. orthorhombic.
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In situ X-ray and neutron diffraction studies of dielectric and piezoelectric materials
Abhijit Pramanick, Anderson D. Prewitt, Krishna Nittala, Christopher W. Brink, Elena Aksel, and Jacob L. Jones
Department of Materials Science and Engineering
University of Florida, Gainesville, FL 32611, USA
G. L. Brennecka, B. A. Tuttle, Journal of Materials Research2007, 22, 2868.
Diffraction during application of dynamic electric fields
X-ray and neutron scattering techniques are some of the most versatile techniques for in situ measurement of structure as a function of temperature or during application of stress or electric fields. This versatility results in part from the ability to design complex environmental and loading devices that can readily be incorporated into the diffraction geometry.
In recent decades, synchrotron and neutron sources at national facilities have brought extraordinary increase in intensity, ancillary equipment, and user support.
However, there also remains a need to advance the state of the art of laboratory-scale equipment, which can be used in the day-to-day research activities at universities and smaller scale research laboratories. Moreover, laboratory-based experiments can provide hands-on research experiences for numerous students who may not be able to travel to a national facility or may require more regular, consistent access to instrumentation.
Fig. 8. Some electronics required for time-resolved data acquisition.
Image from Argonne National Laboratory press release, “X-ray scattering techniques determine how dissolved metal ions interact in solution” (April 12, 2007).
Fig. 9. The 002/200 (a) and the 111 (b) peak during application of a bipolar square wave (±750 V/mm, 1 Hz).
Fig. 3. Diffraction patterns measured during formation of Na0.5Bi0.5TiO3 from reactant oxides and carbonates. Each diffraction pattern was measured for 1 minute during continuous heating to 700°C.
Bi/Ti/O transient phase
Fig. 10. Quantitative analysis of diffraction patterns enable determination of contributions to the piezoelectric coefficient.
Photograph of the Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory (ORNL), the highest flux neutron source in the world.
Mix of Na2CO3, TiO2, and Bi2O3
Photograph of the European Synchrotron Radiation Facility (ESRF) in Grenoble, France.
Photograph of the new OPAL reactor at the Australian Nuclear Science and Technology Organisation (ANSTO) in Sydney, Australia.
Fig. 12. (002) and (200) peaks as a function of stress.
Fig. 4. (a) Cross section of thin film architecture; (b) Diffraction patterns measured during crystallization of a PLZT thin film with 20% Pb excess.
This poster reviews several new techniques that are available at international X-ray and neutron scattering facilities as well as on a new laboratory-scale diffractometer at the University of Florida.
Fig. 11. Photograph of sample mounted in mechanical loading rig and located on neutron diffractometer.
Fig. 13. Profile shape fitting of data in Fig. 12 yields quantitative domain switching and lattice strain outputs.
Phase transitions and lattice parameters
Fig. 5. Diffraction pattern of Na0.5K0.5NbO3 as a function of temperature.
Fig. 14. Example geometry for high-energy X-ray microdiffraction.
Fig. 16. Electric-field-induced domain switching as a function of composition in a compositionally graded ceramic.
Fig. 1. Photographs of the laboratory X-ray diffractometer The curved position sensitive detector spans 120° in diffracted angle.
Fig. 15. Elastic lattice strain of the (111) perpendicular to the crack face during static mechanical loading.
Fig. 6. Sample displacement correction illustrated for intentional displacement of Si powder. Intercept gives true lattice parameter.
Fig. 2. Portion of the measured diffraction pattern of Si powder as a function of measurement time.
Fig. 7. Lattice parameter of Smx/2Ndx/2Ce1-xO2- δ as a function of dopant concentration.
The authors gratefully acknowledge support from the NSF through award number DMR-0746902, the Army Research Office through award number W911NF-09-1-0435, an Oak Ridge Associated Universities Powe Junior Faculty Enhancement Award, the University of Tennessee’s International Materials Institute (IMI) ANSWER program which is supported by NSF DMR-0231320, and Sandia National Laboratories.
The authors are indebted to numerous instrument scientists at national and international facilities including the APS, ESRF, LANL, ORNL, ISIS, and ANSTO for assistance with individual experiments and continuing collaborations. Collaboration with Dr. Juan C. Nino and Dr. Shobit Omar is acknowledged on the CeO2 lattice parameter measurement. Several other current and former University of Florida students are also acknowledged for contributions in this area including Michelle Cottrell, Christopher Dosch, Kyle Calhoun, Paul Draper, Humberto Foronda, Matthew Cothrine, and Billy Valderrama.