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Clive A.
Randall
Professor of Materials Science and Engineering
Director, Center for Dielectric Studies
144 Materials Research Laboratory Building
814-863-1328
randall@matse.psu.edu
Center for Dielectric Studies
www.mri.psu.edu/centers/CDS/. |
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Biographical
Sketch:
Professor Randall received his B.Sc degree in Physics at the
University of East Anglia (United-Kingdom). He then performed
his graduate studies at the University of Essex in Experimental
Physics. He then performed post doctoral studies at Pennsylvania
State University. He later entered the faculty of Material
Science and Engineering in 1994 as an associate professor and
become Full professor in 1999. In 1997, he became the
Director of the National Science Foundation’s Center
for Dielectric Studies at the Pennsylvania State University.
He has had a number of visiting positions during his career
including Shonan Institite (Japan), EPFL (Switzerland), and
University of Sheffield (United Kingdom). In a sabbatical year
(2004-2005) he was a Visiting Fellow at Fitzwilliam College,
at Cambridge University. He was named Fellow of the American
Ceramic Society in 2004. In 2006, he was elected as an Academician
to the World’s Congress of Ceramics. He has published
over 200 papers and holds 11 patents. |
Research
Interests:
• Electronic
Materials |
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Areas
of interest:
Professor Randall utilizes a combination of the material
science approaches of structural-property-process-performance
relations and coupling these with material physics to understand
and design future generation electroceramic materials and devices.
Specific materials the group is studying are ferroelectric
and related materials, microwave, and piezoelectric materials
in a variety of different forms, ranging from crystal structure,
composition, particle and grain size, bulk, film and composites
are considered. Our philosophy is to use extreme application
needs to direct a fundamental study to enable material advances
to be made and implemented. These extreme performance parameters
include a combination of temperature, electric field strength,
frequency- time and size reduction. Under these conditions,
we are concerned with basic mechanisms that control the degradation
under all times of use. These time dependant failure mechanisms
may be controlled through important physical processes such
as electron injection at an electrode or grain boundary, oxygen
vacancy migration, defect dipole rotations, thermochemical
and electrochemical reactions at interfaces. Any of these or
similar phenomena are built into a material through the
fabrication thermal processes and remain in a metastable
state, but ultimately these defects drive the degradation
mechanisms and thereby prevent the implementation of new
materials into a system. Once understanding the sources and
failure processes, our group develops methods through process
modifications or design new materials or chemistries to suppress
these deleterious effects. The above approach has proven extremely
useful in the education of our students and the research conclusions
have attracted collaborations with leading international electroceramic
based companies. |
Technologies
impacted by research:
High frequency high permittivity dielectrics are being
implemented into integrated - tunable Microwave Circuits.
Piezoelectric materials are being developed for diesel
injection systems. High temperature ferroelectrics are
being developed for accelerometers and electronic components.
Our protocols for characterizing interfacial phenomena
in capacitors are being adopted by manufacturers. |
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| Journal
Articles and Publications:
1. The XRD and IR Study
of the Barium Titanate Nano-powder Obtained via Oxalate Route,
A.V. Polotai, A.V. Ragulya, T.V. Tomila, C.A. Randall, et
al., Ferroelectrics 298: 243–251
(2004).
2. Polarization Relaxation Anisotropy in Pb(Zn1/3Nb2/3)O3–PbTiO3
Single-Crystal Ferroelectrics as a Function of Fatigue History,
M. Ozgul, E. Furman, S. Trolier-McKinstry, et al., J. Appl.
Phys.
95(5): 2631–2638 (2004).
3. Investigation of a High Tc Piezoelectric System:
(1-x)Bi(Mg1/2Ti1/2)O3–PbTiO3, C.A. Randall, R.
Eitel, B. Jones, T.R. Shrout, D.I. Woodward, and I.M. Reaney,
J. Appl. Phys. 95(7): 3633–3639 (2004).
4. Influence of Electrical Cycling on Polarization
Reversal Processes in Pb(Zn1/3Nb2/3)O3-PbTiO3 Ferroelectric
Single Crystals as a Function of Orientation, M. Ozgul,
S. Trolier-McKinstry, and C.A. Randall, J. Appl. Phys. 95(8):
4296–4302 (2004).
5. Characterization of Perovskite Piezoelectric Single
Crystals of 0.43BiScO3-0.57PbTiO3 with High Curie Temperature,
S.J. Zhang, C.A. Randall, and T.R. Shrout, J. Appl. Phys. 95(8):
4291–4295 (April 15, 2004).
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