SWEDEN ROUNDTABLES

Site: Royal Institute of Technology (KTH)
SE-100 44 Stockholm, Sweden

Date Visited: 15 October 1997

WTEC: D. Cox (report author), C. Koch, J. Mendel, R.W. Siegel

Hosts:

Attendees:

BACKGROUND

The WTEC team's site visit to Sweden was greatly facilitated by Prof. Rao and Prof. Muhammed, who kindly organized a one-day workshop at the Royal Institute of Technology (KTH) in Stockholm. Groups from across Sweden involved in nanoscale science and technology were invited to send representatives to participate in this workshop. Representatives from the Royal Institute of Technology, Uppsala University, Chalmers University of Technology, Göteborg University, and Lund University, together with program managers from four of the funding agencies in Sweden, contributed to the workshop.

Sweden has made a conscientious effort to have broad-scale information exchange in the area of nanoscale science and technology. There are several consortia (described below) that not only have a multidisciplinary composition but also multiorganizational composition in most instances. As examples, in the area of mesoscopic (20 Å < size < 500 Å) physics, 80-100 people are involved from various institutions in Sweden, and the Nanometer Structure Consortium at Lund has on the order of 100 people involved. Regular meetings are held by the National Board for Industrial and Technological Development (NUTEK) Competent Centers, and the scanning probe community has regular meetings for researchers throughout the country.

PRESENTATION OF CONSORTIUM EFFORTS

After introductory comments, which included a welcome from Prof. Ingmar Grenthe, the Vice President of the Royal Institute of Technology (KTH), overviews of four major consortia in the Nanoscale Science and Technology area were presented:

  1. Clusters and Ultrafine Particles, presentation by Prof. Nils Mårtensson of Lund/Uppsala, the consortium leader
  2. Nanometer Structure Consortium, presentation by Prof. L. Samuelsson of Lund University, the consortium head
  3. Nanophase Materials Consortium, presentation by Prof. M. Muhammed, of the Brinell Center at KTH
  4. Ångström Laboratory, presentation by Prof. C.G. Granqvist and Dr. L. Kiss of Uppsala University

These general consortia overviews demonstrated that significant effort is being expended in nanoscale science and technology throughout Sweden. In addition, there either is or is expected to eventually be, substantial industrial involvement in every consortia. Academia's strong and close ties to the industrial needs of Sweden is a theme that was repeated several times during the workshop.

REPORTS ON THE CONSORTIA

1. Consortium on Clusters and Ultrafine Particles

The Consortium on Clusters and Ultrafine Particles is one of the consortia that makes up the Interdisciplinary Materials Research Consortium (see Table C.I) sponsored by the Swedish Foundation for Scientific Research (SSF), the Natural Sciences Research Council (NFR), and NUTEK. The present Consortium leader is Nils Mårtensson, who is also the new Director of MAX-Lab, the synchrotron facility at Lund. The three primary areas of focus of this consortium are (1) catalysis (clusters - nanophase materials), (2) nanostructured electrodes, and (3) hard materials.

The consortium consists of groups from several different universities and disciplines that collaborate in this area. For example, participants include Uppsala researchers from Physics in Surface Science, Liquid ESCA (electron spectroscopy for chemical analysis), Quantum Chemistry, and Dynamic Electrochemistry; University of Stockholm researchers from Physics in Theory; Linköping researchers in Theory of Spectra; and KTH researchers in Materials Chemistry and Ceramics. In addition there are strong interactions with industrial researchers.

Examples of research being carried out in this consortia are investigations of the fundamental properties of CO dissociation on supported metal clusters. XPS studies of the energy shift in the carbon 1s line have allowed investigators to follow CO dissociation on different nanosize rhodium clusters and conclude that clusters containing on the order of 1000 rhodium atoms supported on alumina were the most adept at dissociating CO. Clusters containing both fewer and greater rhodium dissociated a much smaller fraction of the CO. Similarly, bonding of organic acids on metals, e.g., formate and acetate on Cu(110), is being studied experimentally by XPS and modeled by theory.

These experiments are made possible by the use of the synchrotron radiation at MAX-lab which is located at Lund University. The MAX-II is a third-generation facility, which means that it has been optimized for insertion devices (straight sections). The high intensity X-ray sources at MAX-lab have opened opportunities for X-ray lithography work in two areas that lab researchers are calling micromachining/LIGA process or nanostructuring/IC technology. Potential applications in micromachining include neuro chips, microactuators, microsensors, pressure senders, microparts, filters, flow meters/controllers, and fiberoptics connectors. Potential applications in nanostructuring are sub-0.13 mm microlithography, high speed FETs, biomaterials, fibers and particles, bioelectric sensors, binary diffraction optics elements, optical elements based on CGHs, and high aspect ratio nanostructures.

Another example is the MAX-Lab work on nanostructured semiconductor electrodes for photovoltaics, photoconductors, sensors, electrocatalysis, photocatalysis, electrochromism, electroluminescense, and batteries. The Graetzel cell, which uses particles with controlled morphology, allows optimization of devices that produce electrical energy from light.

2. Nanometer Structure Consortium

During the Stockholm workshop Prof. Lars Samuelson presented an overview of the organization and work being carried out at the Nanometer Structure Consortium. Since this consortium is reviewed in detail at the end of Appendix C by Evelyn Hu, who separately attended a mini-workshop at Lund Luniversity on 14 October 1997, a separate overview of Prof. Samuelson's presentation is not given here.

3. Nanophase Materials and Ceramics Thematic Network at KTH

The Nanophase Materials and Ceramics Thematic Network is based at KTH and is part of the Brinell Centre. It was established in 1996/1997 and is funded by the SSF, KTH, and by participating industries. Prof. Mamoun Muhammed is project leader of the Nanophase Materials and Ceramics Thematic Network.

The Brinell Centre is a newly formed strategic research center coordinating research in materials science in the Stockholm area. The Brinell Centre performs interdisciplinary research and graduate education in materials science, with a focus on advanced engineering materials. It consists of 15 departments and institutes, mostly based in the Stockholm area. The Brinell Centre represents a very broad spectrum in materials science, ranging from basic physics and chemistry to industrial applications of materials science. One type of advanced material is based on nanomaterials. The center maintains a close relationship with both materials-producing and materials-consuming industries. Graduate students will spend at least 6 months work within an industrial company and accomplish a part of their thesis in work at the company.

The research programs at the Brinell Centre are organized within two Interdisciplinary Research Programs entitled (a) Computational Materials Science and Engineering, and (b) Precision Processing of Clean Steels; and three Thematic Networks entitled (a) Nanophase Materials and Ceramics, (b) Materials Science for High Temperature and Aggressive Environments, and (c) Surface Science and Coating Technology. The Thematic Networks cover large scientific areas that are also reflected in the graduate school program.

Thematic Network A: Nanophase Materials and Ceramics

This thematic network encompasses the groups of about six professors in the KTH. Nanophase materials are defined here as materials with a grain size in the 1-100 nm range and are found to exhibit greatly altered mechanical properties compared to their normal, large-grained counterparts with the same chemical composition. For example, nanophase materials are up to five times harder than the normal materials. This thematic network focuses on fabrication and evaluation of the mechanical properties of alumina-based composites containing TiC and TiN nanoparticles. The project aims to study the enhancement of the mechanical properties of alumina composites by dispersion of nanoparticles of titanium carbide and titanium nitride. Scanning probe techniques are commonly used to study the interfaces and fabrication of alumina-based composites. Their mechanical properties are evaluated by nano-indentation, and then the indentation areas are mapped in order to better understand the mechanisms leading to improved mechanical properties of bulk alumina by nanoparticles. Another area of interest involves study of cerium oxide catalysts. Studies have shown that significant improvement in the oxygen storage capabilities of these materials has been achieved with neodymium, calcium, lead, or manganese doping. The program is funded "quite handsomely" by industry. For aerospace applications, nanogranular thermoelectrics based upon opals are being studied in collaboration with Allied Signal Corporation.

4. The Ångström Laboratory

The Ångström Laboratory is located at Uppsala University. It is a center in which expertise in materials science has been gathered together from diverse fields of chemistry, materials science, physics, electronics, etc. The facilities have been designed to expedite high technology research and there are specially equipped laboratories to offer optimal conditions for experiments, for example, rooms with extremely high air purity that are free from vibration. Four strategic research programs have been established at the Ångström Laboratory: the Center for Advanced Micro-Engineering, the Ångström Solar Center, the Batteries and Fuel Cells for a Better Environment Program, and the Energy Systems Program.

As an example of the lab's world-class capability is its recent purchase and installation of a $1 million apparatus to fabricate large quantities of ultrafine particles. The apparatus can be operated in several different modes, such as Gas Evaporation Mode or Direct Gas Deposition Mode, depending on the material to be fabricated. The equipment will allow researchers to produce high purity, nearly perfect nanocrystals with a narrow size distribution (2-3 nm in diameter) at a very high production rate (20 gm/hr). Several types of nanoparticles are being produced and examined by different researchers. These include active metal particles, isolated metal particles, nanochains of ferromagnetic nanoparticles, and ceramic nanoparticles. Studies include fabrication of Fe-Ag films for experimental investigation of giant magnetoresistance (GMR) properties, as well as use of "ordinary" nanoparticles to fabricate films from nanopaste for studies of their electrical and thermal resistivity properties.

REPORTS FROM FUNDING AGENCIES OF SWEDEN

In addition to presentations overviewing consortia efforts, four presentations were given by managers from four different Swedish funding agencies describing nanoscale science support in their respective agencies. Summaries of these presentations follow.

NUTEK

Dr. H. Hakansson stated that NUTEK budgets are being reduced to about SKr. 26 million for 1998, whereas over 50 applications have been received the request support in the amount of SKr. 150 million. NUTEK nanoscale program areas are (a) active materials and nanofunctional materials; (b) microsystems technology; and (c) peripherals.

Natural Sciences Research Council (NFR)

The Natural Sciences Research Council presentation by Dr. U. Karlsson emphasized that the NFR primarily supports basic research. The budget for physics is about SKr. 82.5 million, of which about 25% is for condensed matter physics. It was estimated that about 20-30% of the total NFR chemistry and physics budget supports nanoscale science initiatives, continuing the NFR history of strongly supporting nanoscale science efforts. It supports the Materials Science Consortia, of which the Nanometer Structure Consortium and the Clusters and Ultrafine Particles Consortia are part, and it also supports the National Facility at Göteborg University, which consists in part of experimental physics groups from Lund, Göteborg, Uppsala, Stockholm, and Umea Universities. Interestingly, the NFR also supports "senior research positions." At present it provides support for positions in the following areas: low dimension structures, mesoscopic physics, surface chemistry, and theory (4 positions). Two other positions are presently under consideration, one in cluster chemistry and another in the physics of small structures.

Swedish Foundation for Strategic Research (SSF)

The Swedish Foundation for Strategic Research is a relatively new organization, created in January 1994 with a SKr. 6 billion budget. As described by Dr. Marika Mikes-Lindback, the goal of the foundation is to support scientific, technical, and medical research. One objective is to build up competence in a field and then get companies founded to commercialize products in that field. Projects are 100%-funded by SSF. There are six main programs, of which five are vertically oriented and one (Materials) is horizontally oriented. Two programs have large components of nanoscale science and technology:

Interdisciplinary Materials Research Consortia, receives about SKr. 42 million in support, about 25% of that for projects involving nanoscience. Table C.1 lists the Interdisciplinary Materials Research Consortia, together with their objectives and 1998 funding levels.

Table C.1. Sweden's Interdisciplinary Materials Research Consortia & 1998 Funding Levels

Consortium

Leader

Objectives

1998 SKr (M)

Ångström Consortium

Soren Berg

Methods and processes for preparation of surface coatings with controllable structure and composition

5.9

Thin Film Growth

Lars Hultman

Growth of thin films for power electronics, for magnetic multilayers, and for wear-protective coatings

6.3

Nanometer Structures

Lars Samuelson

Nanometer structures and their applications; fabrication and characterization

5.5

Clusters and Ultrafine Particles

Nils Mårtensson

Physical and chemical methods for synthesizing and characterizing clusters and ultrafine particles

3.3

Biomaterials

Bengt Kasemo

Physics and chemistry of surfaces and their interaction with biological systems

5.7

Theoretical and Computational Materials Physics

Bengt Lundqvist

Theoretical and computer-aided methods and models and application to technologically relevant materials

4.7

Computer-Assisted Materials and Process Development

Bo Sundman

Creation of a computer-based tool for materials and process development

4.1

Superconducting Materials

Tord Claeson

Thin film HTC materials preparation and characterization and optimization of their properties and applications

5.7

High Speed Electronics, Photonics, and Nanoscience/Quantum Devices receives SKr. 40 million in support, of which ~ 25% is targeted for nanoscience. This program is being established because Sweden believes that the microelectronics area is highly strategic for modern society and affects all sectors of industry as well as the information society generally. Its primary goal appears to be to open the pipeline to a continual supply of well-trained and -educated researchers to industry. It is a joint strategic research program and graduate school at the Royal Institute of Technology (KTH), Chalmers University of Technology and Göteborg University (CTH/GU), and at Lund University (LU). The joint program is based on three research proposals submitted by CTH/GU (Components for High Speed Electronics), LU (Nanoscience) and KTH (High Speed Electronics and Photonics), all of which are judged to have current relevance to the Swedish microelectronics industry. The goal of the joint program is to "create research results within these research sub-fields, but specifically also to create novel ones by a strategic cooperation within and between the sub-fields and Swedish electronics industry." The goal of the graduate school is to "provide Ph.D.s and Licentiates with a education which fulfills both the short term and the long term needs of the Swedish society and in particular the Swedish industry." After the initial four-year startup period, students will be graduating at a rate of 15 per year, with 80% going to industry.

Defense Research Establishment (FOA)

The FOA is Sweden's national defense research establishment. It has about 1,000 employees and an annual budget of SKr. 600 million. The defense research must function as a link between the possibilities offered by science and technology and the needs of the armed forces of Sweden. A presentation entitled "Nanostructured Materials at FOA" was given by Dr. Steven Savage of the FOA's Department of Materials. There has been a proposal presented to FOA to free up about 3% of the organization's funds for nanoscale research programs. At present, there are only some small efforts that involve nanoscale materials within existing projects:

In an attempt at international collaboration, the FOA is participating in an EU project application for fabrication and study of nanostructured light materials. The coordinator of this project is Brian Cantor of Oxford University.

INDIVIDUAL PRESENTATIONS FROM RESEARCH GROUPS

The last part of the workshop at KTH was devoted to presentations from individuals who gave brief overviews of the nanoscale science and technology research efforts in their individual groups.

Prof. David Haviland, now at KTH, described his efforts in nanostructure physics. He uses lithographically defined nanostructures to study electronic transport phenomena such as Coulomb blockage, spin-dependent transport, and theory involving quantum optics in nanostructures and diffraction optics in nanostructures. Prof. Haviland collaborates closely with Profs. P. Delsin and T. Cleason of the Single Electron Group at Chalmers.

Prof. K.V. Rao of KTH described his group's research in large scale applications of soft magnetic materials. The work is entitled Functional Nanometric Science and consists of three primary thrusts:

  1. Production by several different techniques such as thin film deposition using rf laser ablation, rf sputtering, and e- beam deposition; rapid solidification technology such as melt spinning to produce GMR materials; and chemical co-precipitation techniques.
  2. Characterization using surface probe microscopy; atomic force, scanning tunneling, and magnetic force microscopy (AFM, STM, and MFM) are key techniques.
  3. Applications of nanostructures, under study as magnetic dots, novel GMR materials, high Tc-based tapes from nanosize precursors, nanolithography and carbon nanotubes and fullerenes as nanoscale electrodes.

Prof. Arne Rosen of Chalmers University of Technology and Göteborg University presented a detailed overview of the nanoscale science being carried out in his Molecular Physics Group. The title of his talk, "Clusters, Fullerenes, Nanotubes and Nanowires: New Building Blocks in Nanoscience," accurately describes the presentation. A brief description of the key areas of interest is given here. The key research areas in his group cover six main themes:

  1. surfaces and catalysis
  2. metal clusters
  3. fullerenes and nanotubes
  4. combustion engine research (there is a center dedicated to this work)
  5. medical-related research
  6. related other projects

Two areas that are almost entirely devoted to nanoscale work are the metal cluster and the fullerene and nanotube research areas. In both areas there is a strong experimental effort, coupled with a strong theoretical effort. For example, the metal cluster experimental approach is directed towards studies of reactivity and electronic properties of free (molecular beam) metal clusters and studies of size-selected deposited metal clusters. The theory then examines electronic structure of free metal clusters, calculations of electronic structure for adsorbates on clusters, ab initio molecular dynamics (MD) calculations of clusters and adsorption on clusters, MD simulations of thermal properties, and simulations of cluster atom collisions. The approach taken in this group closely ties experiment to theory, as well as basic science to applied science.

Prof. Bengt Kasemo oversees nanoscience research that consists of three main thrusts:

  1. Nanofabricated model catalysts. In this thrust, modern micro- and nanofabrication methods are used to provide a new avenue to prepare controlled model catalysts that are expected to realistically mimic real supported catalysts. These catalysts consist of 2-D arrays of active catalysts deposited on active or inactive support materials. Particle size, shape, separation, and support can be systematically varied. The structures are easily accessible to scanning probe imaging and surface analysis techniques. The 2-D analogs of supported catalyst is illustrated by Pt particles in the size range 10-500 nm deposited on alumina and ceria manufactured by electron beam lithography. The sintering mechanisms of Pt particles on support materials and the role of oxygen supplied from support material (e.g., ceria) in catalytic reactions are being studied.
  2. Nanofabricated metal particles. Nanofabrication is used to create arrays of Ag particles of 100-200 nm in size and of different shapes in order to study the influence of these parameters on the ability to detect individual biological molecules using surface enhance Raman spectroscopy. Kasemo's group has successfully shown this for colloidal Ag suspensions (3-D) as well as 2-D arrays of nanofabricated Ag particles made by electron beam lithography.
  3. Colloidal lithography for biomaterials applications. Different methods are being explored to create surfaces of interest for biomaterials testing and applications by using large area topographic patterning of nanoscale features by colloidal lithography (8-200 nm). Specifically of interest is how nanometer-scale topography influences biomolecule and cell adhesion and function at surfaces.

Prof. Tord Claeson described the work in Nanoelectronics, Nanoscience at Chalmers University of Technology. Approximately 100 people are involved in this research effort. The main areas of interest are in high electron mobility transistors, electron hole drag phenomena, fabrication of junctions with small capacitance, phase coherent transport with possible applications to superconducting mirrors, and biological applications in which they have shown that nanoscale TiO2 fibers are engulfed by cells without cell collapse, whereas silica fibers cause cell collapse.

Mats Jonson overviewed the theoretical efforts at the Göteborg University. About 15 theorists are involved in study of mesoscopic systems. Efforts are directed towards theoretical understanding of phase coherence in mesoscopic systems, strong electron correlation effects, nonequilibrium situations, high frequency microwave response, and mixed metal superconducting materials.

SUMMARY

In the general discussion at the end of the workshop, the following themes were emphasized:


Published: September 1999; WTEC Hyper-Librarian