Executive Summary
Thomas Palstra holds a chair in Solid State Chemistry and has a leading research group
in electric conduction, magnetism, superconductivity and ferroelectrics. His present
scientific interests include crystal structure-property relationships of transition metal
oxides, organic conductors and organic-inorganic hybrid materials. He has coauthored
approximately 190 manuscripts which were cited more than 12000 times, resulting in a
Hirsch-index of 54. He was elected in 2010 member of the Dutch Royal Academy of
Sciences.
Prof. Palstra has fulfilled a number of management responsibilities including
vice-dean and dean of the Faculty of Mathematics and Physical Sciences (2008-2009),
and is presently director of the Zernike Institute for Advanced Materials. He was
responsible for the RuG Sectorplan Physics and Chemistry (2009) and for the selfevaluation of the Zernike Institute (2010). The latter resulted in a no.1 position in the
ranking of the six top-researchschools, ex aequo with NOVA, astronomy. During his
tenure as director, the Zernike Institute ranked worldwide as no.9 in Materials Research
Institutes according to the Times Higher Education index, straddled between Princeton
University and MIT.
Research Mission of the Solid State Chemistry Laboratory
The aim of the current research program is to utilize displacive, spin-, charge and orbital
degrees of freedom to control the electronic and physical properties of metals, inorganic
materials and molecular organic compounds. The research takes place on the highest
international level, and is competitive with that of the best universities worldwide. This
research will train Ph.D. students and Post-docs to become leading researchers in industry
or academia.
Research Program
We synthesize materials in bulk and thin film form, and study the relationship between
the crystal structure and functional, electronic and physical properties. Theoretical insight
is obtained through band structure calculations. Our unique capability is a variety of
synthesis methods, both for bulk and thin film materials, a large range of temperature,
pressure and magnetic fields over which both the crystal structure and the electronic
properties can be studied. We have interest in highly correlated electron systems, in
particular A: transition metal oxides,TMO, B: molecular organic conductors (C60 ,
pentacene and hybrid materials), and C: multiferroic materials.
Strategy
Transition metal oxides form a class of materials with unparalleled diversity in physical
properties. They both serve as model compounds for fundamental research and also find
practical use in various applications. After my arrival in 1996 in Groningen, we have
augmented our expertise in physical characterization with synthesis and
crystallography.The focus over the last years has been on understanding and controlling
electronic properties using lattice, spin- and orbital degrees of freedom. The focus into
the future will expand towards 1. exploiting new physical properties at lateral interfaces 2.
utilizing this knowledge of competing electronic phases in device-like geometries.
Organic conductors are considered as viable alternative for low-cost electronics.
Furthermore, molecular organic compounds exhibit physical properties which can be
treated on the same footing as those of the TMO, including non-conventional
superconductivity, strong electron-electron and electron-phonon interactions. The focus
of our effort remains on fundamental processes contributing to the electronic mobility of
systems, including the consequences of polymorphism, impurities, grain boundaries. This
focus is expanded with investigations of device performance, thin film transistors, surface
properties, development of new materials (co-crystals and hybrid organic/inorganic
materials).
Multiferroic materials combine magnetic and electric order. For most materials these
properties are mutually exclusive as they are based on either partially filled or formally
empty d-orbitals. A small class of materials combines these orders. This makes it possible
to control electric/magnetic properties by magnetic/electric fields, respectively. We study
the nature of the magnetoelectric coupling by combing structural studies with electric
response in magnetic fields.
Research Group
The group consists besides myself of Prof. B. Noheda, who joined the group in 2004 as
Rosalind Franklin fellow and who was awarded a prestigious NWO-VIDI fellowship in
2004. The group is complemented by Prof. R. de Groot, who fills a professorship as
‘buitengewoon hoogleraar’ in Electronic Structure Calculations. In 2005 G. Blake was
awarded also a NWO-VIDI fellowship. I supervise approximately 4 PhD students, and
have been (co)promoter of 12 PhD students. The group has two technical associates, ing.
J. Baas and Mr. H. Bruinenberg and a secretary, Mrs. H. van Mil. The activities can be
found at:
http://www.rug.nl/fwn/onderzoek/programmas/scheikunde/solidStateChemistry
Funding for the research is granted by Chemical Sciences CW, Physics FOM ,both part
of NWO- the National Science Foundation, Economic Affairs EZ through NanoNed,
European Community, the University of Groningen, and the Center of Excellence
Program of the Zernike Institute.
Citation from the Self-Evaluation of Science and Technology RuG 1996-2004
“This excellent group, established in 1996, is focusing on the electronic properties and
charge transport properties of a wide range of materials ranging from transition metal
oxides to organic conductors with the view that these systems have common
characteristics, in particular strong electron correlations. The group is internationally well
recognized and is among the most active groups studying highly correlated systems.
Particularly remarkable is the combination of chemistry and physics skills.”
Accomplishments
During my Ph.D. until 1986, I studied the magnetic and electronic transport properties in
intermetallics. This research attracted considerable attention with my discovery of the
URu2Si2, the first antiferromagnetic superconducting system. After a short diversion to
methane chemistry, I resumed this kind of research at Bell Laboratories on the recently
discovered high temperature superconductors. My discovery of flux motion put a firm
basis for the technological relevance of these materials in high magnetic fields and large
electrical currents. As permanent staff member, my research concentrated on transport
properties of organics and oxides. Important was our discovery of C60 superconductivity,
and contributions to Colossal MagnetoResistance. In Groningen (from 1996) my
approach widened considerably: we started a coherent synthesis effort, including crystal
growth, and make extensive use of X-ray and neutron scattering. This meant that the
emphasis shifted from an itinerant description to a local perspective. The synthetic effort
was expanded by thin film pulsed laser deposition by Prof. Noheda..
As is common for materials science, the research involves many aspects of physics,
chemistry, and crystallography. Therefore, it is very important to have good connections
to and extensively collaborate with people that use complementary techniques. Also,
theoretical contributions are instrumental for progress and understanding.
University of Leiden 1981-1986 Ph.D.
For my Ph.D. degree I studied three separate intermetallic compounds. (La,Al)Fe13 is an
unconventional iron-based magnet, with a transition from a ferromagnetic to
antiferromagnetic state with large magnetoresistive effects. Small band gap uranium
based intermetallics such as UNiSn resulted in small band gap correlated behavior, a field
that recently has become very prominent. Finally, I studied heavy fermion systems based
on the prototypical compound CeCu2Si2. We systematically replaced Cu with other 3d,
4d- and 5d-metals and Ce by U. This way we noted that strong correlations are located at
the boundary between Pauli-pramagnetic and antiferromagnetic states. This way we
discovered superconductivity in URu2Si2 near 1K, below an antiferromagnetic transition
at 17.5K. Using specific heat experiments, we showed that the same electron system is
responsible for the magnetic as the superconducting order.
Bell Laboratories 1987-1989 post-doc and 1989-1996 member of Technical Staff
As a post-doc I studied the then newly discovered high-temperature superconductors. I
discovered that the origin of the broadening of the resistive transition in magnetic fields is
related to flux motion. The small pinning energies are caused by the two dimensional
nature of these superconductors. This results in a rapid suppression of the critical current
in magnetic fields, and limits the application of these materials.
As staff member I chose to refocus on organic conduction and cluster materials. We
studied intensely organic radical compounds as new possible superconductors. After the
invention of Krätchmer to synthesize bulk quantities of C60, we discovered
superconductivity induced by alkali doping. We studied many aspects of charge transport
including pressure, magnetic fields, stoichiometry, and the first fabrication of C60 based
transistors.
The cluster compounds we studied are unique in the sense that it was possible to change
to valence state from neutral to +1, +2, and +3 by adding electron accepting groups in
interstitial voids. This way we could change the electronic properties only by changing
the valence state.
In the early nineties the cluster research changed into studying the emergent colossal
magnetoresistance materials. We found that chemical pressure has profoundly different
electronic effect on the magnetoresistance as hydrostatic pressure, originating from a
different crystallographic response.
Vice Dean Faculty of Mathematics and Natural Sciences FWN (2008-009)
My responsibilities covered, besides being member of the Faculty Board, the education
programs of the entire faculty. The activities cover aspects ranging from outreach
programs, curricular development and assessment to accreditation of the programs. FWN
has three education institutes: Natural Science and Technology, Informatics and
Cognition, Life Science, with each an Education Director and support staff as well as an
Faculty Education Office (FOB). The Education Directors and Head FOB reported to me.
Outreach : The faculty has increased its enrolment from less than 500 in 2005 to approx.
750 students in 2008. The outreach programs take place under the umbrella of
ScienceLinX and the RuG Discovery Truck. In 2009 sizable funding near 1.4ME has
been acquired for these activities from ‘Platform Beta Techniek’ in the Sprint program.
To increase the enrolment in Physics and Chemistry a proposal is formulated for the
‘Sectorplan Natuurkunde en Scheikunde’ including funding for outreach activities,
curriculum development and new Chairs in specific areas.
Quality : The Faculty is developing a uniform Quality Assurance system in which new
legal requirements are being adopted with clear uniform procedures and responsibilities.
Students and staff actively contribute to a cycle of actions: Plan, Do, Act, Check. The
Faculty Board has made the Basic Qualification Education (BKO) a mandatory part of
curriculum development, and made staff available to assist with the engagement and
professionalization of educators.
Programs : General procedures and guidelines within the faculty are made more uniform
to offer a transparent structure for all students and staff members. Various bachelor and
master programs request specific attention. The Education Research group has been
restructured to optimize the education support for the staff as well as the education
research effort. For Industrial Management and Engineering a new management structure
and curriculum is being developed, to enable to channel this new education program to be
embedded in research programs. The physics programhas been analyzed and various
aspects are detailed which need improvement.For Biomedical Technology new impetus
from our faculty has been provided.
Excellence : In the Bachelor program the faculty participates in the Honours College, for
which the FWN contribution of 25 ECTS has been proposed. The program intends to
start in the year 2009/2010. The Masters program offers Topprograms for four research
directions, for which a new uniform definition, selection procedure and funding was
established.
International Relations: an exchange program has been granted by the EU for student
and staff exchange between the European universities of Bochum, Heidelberg, Uppsala
and he Japanese universities of Osaka, Kyoto and Sendai. This is sponsored by the EU
and I was the European coordinator.
The faculty should engage in changes in which students are offered a broad range of
programs with ample choices to suit their interest, and to prepare them for a career in
science, industry or society. As society continues to offer a more global perspective, our
programs should reflect this trend in enrollment, program and staff.