IRES 2011: Undergraduate Research in
Leoben, Austria
Humberto Foronda
Materials Science and Engineering, University of Florida, Gainesville, FL, USA
40.0
39.5
0.0
0.2
0.4
0.6
X Axis Title
0.8
1.0
0
43.00
50.00
100.0
150.0
200.0
245.0
265.0
279.0
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Population:
25,227
Official
Language:
German
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Specializes in Mining, Metallurgy, and Materials
Number of Students: 2,764
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• Insititut für Struktur und Funktionskeramik
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• 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
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6

NBT-Fe 0.5%
Grain
Pullout
NBT-Fe 2.0%
Grain
Pullout
Fe
•Electron microprobe image (left). Same image with focus on
Fe(right)
•0.5% noticeably homogenous throughout sample
Fe clusters
Grain
Pullout deposits(clusters) around pores, noticeably inhomogeneous
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NBT-Mn 0.5%
Grain
Pullout
NBT-Mn 2.0%
Grain
Pullout
Mn
Mn clusters
•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
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Na
Grain pullout
Magnified Images of 2% Mn-NBT
Grain pullout cluster
Mn
Bi cluster
Grain pullout
Grain pullout
Reduction in Bi
• 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.
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•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)
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6
7
9
• 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
% BT Transition Temp in
Darmstadt (Celsius)
205
225
225
Transition Temp in UF
(Celsius)
265
285
265
• expect to see it as an anomaly in the peak position of the mode at 620 cm-1
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E-Field Poled PZT sample with
Vicker’s
Indentation
(Anisotropic)
Cracks parallel to Efield 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.
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Sample
PZT_T_P01 Indenation 1
PZT_T_P01 Indenation 2
PZT_T_P01 Indenation 3
PZT_T_P01 Average
Parallel(μm) Normal(μm) Parallel (μm) Normal (μm) Parallel (μm) Normal (μm)
167 276.5
173.4
287.9
166.2
274.6
159.3
165.3
166.2
282.6
273.7
275.1
160.3
161.6
165.1
292.3
278.3
286.2
155.9
156.0
159.4
269.5
272.6
272.2
PZT_T_P02 Indenation 1
PZT_T_P02 Indenation 2
PZT_T_P02 Indenation 3
PZT_T_P02 Average
PZT_T_P03 Indenation 1
PZT_T_P03 Indenation 2
PZT_T_P03 Indenation 3
PZT_T_P03 Average
193
190.8
188
190.6
173.1
180.8
180.8
178.2
206.3
213.4
206.8
208.8
221.2
227.3
224.5
224.3
204.7
185.2
190.9
193.6
176.9
182.9
189.4
183.1
225.0
227.6
227.4
226.7
252.2
247.7
244.1
248.0
Cracked and Measured by Dr. Bermejo in 2009
Cracked by Dr. Bermejo but measured by Humberto in 2011
Cracked and measured by Humberto in 2011
1.
Poled at 2kV/mm, heated to 150 celsius
2.
Poled at 2kV/mm, heated to 150 celsius, 50 MPa load
3.
Poled at 2kV/mm, heated to 75 celsius, 50 MPa load
182.13
179.31
229.2
231.58
204.63
229.78
188.69 230.1866667
174.18
177.93
185.62
179.24
234.11
240
236.63
236.91
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• 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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