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Humberto Foronda

IRES 2011: Undergraduate Research in Leoben , Austria. Humberto Foronda. Materials Science and Engineering, University of Florida, Gainesville, FL, USA. Support : NSF OISE-0402066, DMR-0746902, and OISE-0755170, Army Research Office W911NF-09-1-0435. Leoben,Austria. Population: 25,227

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Humberto Foronda

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  1. IRES 2011: Undergraduate Research in Leoben, Austria HumbertoForonda Materials Science and Engineering, University of Florida, Gainesville, FL, USA Support: NSF OISE-0402066, DMR-0746902, and OISE-0755170, Army Research Office W911NF-09-1-0435.

  2. Leoben,Austria Population: 25,227 Official Language: German

  3. Montanuniversität Leoben Specializes in Mining, Metallurgy, and Materials Number of Students: 2,764

  4. Life at the Institute • Insititut für Struktur und Funktionskeramik

  5. Research • Investigation of Sodium Bismuth Titanate with Iron and Manganese at different percentages with an electron microprobe • Raman Spectroscopy on various compositions of NBT-BT processed at the University of Florida and Darmstadt • Investigation of crack propagation in Vickers Indentations on conditioned Lead Zirconate Titanate

  6. Electron Microprobe

  7. NBT-Fe • Electron microprobe image (left). Same image with focus on Fe(right) • 0.5% noticeably homogenous throughout sample • 2.0% forms Fe-rich deposits(clusters) around pores, noticeably inhomogeneous NBT-Fe 0.5% Fe Grain Pullout NBT-Fe 2.0% Fe clusters clusters Grain Pullout Grain Pullout

  8. NBT-Mn Mn • Electron microprobe image(left).Same image with focus on Mn (right) • 0.5% noticeably homogenous throughout sample • 2.0% has Mn-rich deposits, noticeably inhomogenous NBT-Mn 0.5% Grain Pullout NBT-Mn 2.0% Mn Grain Pullout clusters

  9. Magnified Images of 2% Mn-NBT • Original image of magnified surface of NBT-Mn 2% • electron microprobe conducts search on Mn, cluster of Mn, inhomogeneous • Electron microprobe conducts search on Na, cluster of Na, • Electron microprobe conducts search on Bi, reduction in bismuth. Mn cluster Grain pullout Grain pullout Na Bi Grain pullout Grain pullout cluster Reduction in Bi

  10. Raman Spectroscopy • Examines vibrational modes in a sample • Sample was measured with a source of monochromatic light, recording only the inelastically scattered photons • Incident Photon can be absorbed by molecule (Stokes Scattering) • Molecule can lose energy (Anti-Stokes Scattering)

  11. Raman Spectra for NBT-BT

  12. Raman for NBT-BT • Raman Spectra is plotted raw data. • Analyzing data through peak fitting helped us find transition temperatures • According to literature on NBT-based materials, the mode at 620 cm-1 represents vibrations of the BO6 octahedra occurring along the c-axis, showing a change in the symmetry or tilting of the octahedra • expect to see it as an anomaly in the peak position of the mode at 620 cm-1

  13. Indentations E-Field Poled PZT sample with Vicker’s Indentation (Anisotropic) Cracks parallel to E-field shorter due to energy lost when domains switched from perpendicular to parallel. • Life expectancy of poled samples were investigated. • Repeated crack length measurements which were conducted two years ago in order to compare and discover a potential aging effect.

  14. Recorded Measurement • Poled at 2kV/mm, heated to 150 celsius • Poled at 2kV/mm, heated to 150 celsius, 50 MPa load • Poled at 2kV/mm, heated to 75 celsius, 50 MPa load

  15. Recorded Measurements

  16. Future Work • Prepare NBT results from Austria for publication • Continue work on NBT-BT temperature dependant measurements • Potentially continue measurements of electromechanical coupling factor

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