Please take a look at our recent research news:
Seasonal and Diurnal Variations in Atmospheric and Soil Air 14CO2 in a Boreal Scots Pine Forest, Palonen, V. M., Pumpanen, J., Kulmala, L-M., Levin, I., Heinonsalo, E. J. & Vesala, T. V. 2018 julkaisussa : Radiocarbon. s. 1-15
Tracing grog and pots to reveal Neolithic Corded Ware culture contacts in the Baltic Sea region (SEM-EDS, PIXE), Journal of Archaeological Science 91: 77–91. Holmqvist, E., Å. Larsson, A. Kriiska, V. Palonen, P. Pesonen, K. Mizohata, P. Kouki and J. Räisänen 2018.
Materials properties analysis and tailoring
The current research focus is on materials of importance for nanotechnology, micro- and optoelectronics, spintronics, fusion technology and particle detectors. Their properties are studied by applying various ion beam, X-ray, ultrasonics and interferometry based techniques as well as by computational means. The respective equipment employed for these activities are described in detail under the various laboratory profiles.
Ion beams offer unique opportunities for modifying various characteristics of metals, semiconductors, ceramics, plastics and organics, and of fabricating new materials from them. They are also widely used to study and produce thin films. Our research program includes studies aiming at improving e.g. friction, wear, hardness, corrosion resistance, and optical and electric properties of materials.
Versatile properties of synchrotron radiation make it one of the main tools in the research of material physics. Inelastic x-ray scattering and absorption spectroscopy is used as a tool to characterize the electronic properties of novel materials, the physics of the batteries of mobile phones is one example of applications.
Ion beam analysis
The areas of research with the ion beam analysis are the physical processes taking place in solid matter during and after irradiation of energetic ions. These areas involve:
- Interaction and slowing-down of energetic ions in solids
- Ion irradiation induced effects on the structure of matter
- Interaction of defects, host atoms, and implanted atoms
- Diffusion and solubility of impurity atoms
- Production of new materials
- Analysis of ion-implanted and irradiated Materials
- Ion beam technology offers opportunities for research and technology of modifying various characteristics of metals, semiconductors, ceramics, plastics and organics, and of fabricating new materials from them.
The experimental facilities of the laboratory include:
- TAMIA, a 5MV tandem accelerator, which is mainly used for
- Accelerator Mass Spectrometry (AMS)
- Elastic Recoil Detection (ERD)
- In situ irradiation and PAS/electrical characterization of materials at variable temperatures
- Rutherford Backscattering
- KIIA, a 500kV implanter
- Rutherford Backscattering including channelling
- Sputtering device for serial sectioning of radiotracer implanted diffusion samples.
Laboratory for nanomaterials
In the laboratory for nanomaterials the efforts of our research are focused on study of fundamental and applied aspects of nanosystems and nanostructured materials, formed using ion and cluster beams. Both top-down and bottom-up strategies are followed with a key question of how surface and embedded nanostructures can be formed and modified at will to acquire the desired properties and functionality? For this, advantages offered by cluster and ion beams for manipulation with matter at the nanoscale are applied for materials modification, synthesis, characterization and functionalization.
Cluster self-organization and aggregation on the surface, thermal, structural, electrical and magnetic properties are in the focus of the Lab activity. An urgent need for successful nanoelectronic applications in comprehensive understanding of size- and spin-dependent quantum effects, mesoscopic transport, thermal and mechanical properties of low-dimensional structures (thin films 2D, nanowires 1D and nanoparticles 0D) are addressed.
In the laboratory for nanomaterials the following experimental techniques are available:
- Ion implantation
- Cluster deposition - FAcility for NAnostructures DEposition (FANADE)
- Dual e-beam and ion sputter deposition
- Ion beam dry etching facility for nanostructuring and downsizing
- Atomic Force Microscopy (AFM) / Scanning Tunneling Microscopy (STM)
- Low Energy Electron Diffraction (LEED)
- Auger Electron Spectroscopy (AES)
- Low Energy Ion Deposition (LEID, under development)
- Ultra-High Vacuum (UHV) Variable Temperature Atomic Force Microscope (AFM) / Scanning Tunneling Microscope (STM)
- Cryogen-Free Dilution Refrigerator System (~10mK)
- Furnaces for sample annealing (up to 1500 ℃)
- Equipment for terahertz spectroscopy
Prof. Jyrki Räisänen
tel. +358 02941 50082
PL 43 (Pietari Kalmin katu 2)
00014 HELSINGIN YLIOPISTO