Petr Šittner from the Institute of Physics has become one of the laureates of this year’s Academy Premium awarded by the Czech Academy of Sciences. The president of the Academy of Sciences only announced the four winners for the first time in the fourteen-year history of the prominent science award, in a departure from the traditional prize-giving ceremony.
The Academy Premium supports excellence in science. “We want to create favourable conditions to help our top researchers unlock their potential for the benefit of the Academy of Sciences and Czech science as a whole,” said Eva Zažímalová, the president of the Czech Academy of Sciences. The grant associated with the award amounting up to 30 million CZK can be used by the beneficiaries to cover the research and payroll costs or the acquisition of technical equipment over the period of six years.
The Academy Premium will support Petr Šittner in performing a systematic study of deformational mechanisms in metal alloys that relate to shape-memory alloys but unlike them display no martenzitic phase transformation (non-diffuse modification of the structure of a solid matter occurring as nucleation and interface advance), with their structure capable of being continuously and reversibly modified to a similar range under mechanical strain (supercritical elasticity).
The research of martensitic phase transformations and thermomechanical behaviour
Petr Šittner has focused on the systematic study of deformational mechanisms in shape-memory alloys. His major research area includes martensitic phase transformations and thermomechanical behaviour. Shape-memory alloys are metallic materials manifesting themomechanical properties that are completely unusual in metals, such as extreme reversible deformability, shape-memory phenomenon or the capacity to provoke mechanical motion at the change of temperature. Nowadays shape-memory alloys are mainly used in areas such as medicine, aviation, automotive industry, or consumer industry.
“Given that we still don’t succeed in developing superelastic alloys with shape-memory and sufficient resistance to mechanical fatigue, we are looking to create new metals manifesting a non-hysteretic reversible deformability in a broad temperature range achievable by a physical deformation mechanism other than martensitic phase deformation occurring through nucleation and the advance of internal interfaces. Such materials provide a wide range of future application in robotics, medicine, space technologies, simply in all domains where superelastic shape-memory alloys fail due to a premature fatigue damage and fracture under cyclical mechanical strain. There is still probably a long and challenging way to go to develop such materials,” says RNDr. Petr Šittner, CSc., commenting on the goal of his research.
The first results published on this direction have shown that mono-crystalline metal fibres from NiCoFeGa alloy have the capacity to deform reversibly and non-hysteretically up to ~10% pull deformation and ~1.5 GP and the strain throughout millions of cycles without the slightest modification of the non-linear stress-strain curve, in a similar way as in the case of linear elasticity of common metals with the deformation of up to ~1 % of the deformation range.
Petr Šittner will seek to find the chemical composition and the parameters of thermomechanical processing of multi-element metallic alloys manifesting supercritical elasticity. The research will necessarily require the systematic study of the changes in the structure of the material under mechanical strain, which can be performed on common volume materials exclusively using neutron or high-energy synchrotron radiation. Alternatively, samples can be prepared in the form of ultra thin metallic fibres which enable the performance of the same investigation using laboratory X-ray sources and modern X-ray and electron microscopy in-situ methods; this preparation requires only a small amount of materials.
A secondary goal of the research to be carried out by the laureate and his colleagues as part of the Academy Premium is to introduce these modern experimental methods and technologies into the research at the Institute of Physics.
Petr Šittner, having defended his dissertation thesis at the Institute of Physics of the Czech Academy of Sciences, worked as an assistant researcher at the Technical Faculty of the Mie University in Japan for several years, where he joined professor Tokuda’s team and introduced a new direction in theoretical and experimental research on themomechanical behaviour of SMAs under generic strain; this research was later followed by a number of top research teams in the US, France or China.
After returning to the Czech Republic, he continued to research martensitic transformations in cooperation with Václav Novák form the Department of Metals at the Institute of Physics, and Michal Landa from the Institute of Thermodynamics of the Czech Academy of Sciences. In 2000, in cooperation with Petr Lukáš, he was entrusted with his first research project targeting the use of neutron scattering for studying deformation processes in metallic materials manifesting martensitic phase deformations. He continued this research by performing systematic experiments using high-energy synchrotron radiation at ESRF in Grenoble in France. In recognition of his results in diffraction research of localized deformation mechanisms of thin fibres of NiTi memory-shape alloys published in Science, he and his team received the Siemens Award for the best result in basic research in 2016.
After 2005, Petr Šittner led the FZU team in a series of prestigious European projects, some of which focused on the use of NiTi alloys in technical applications. A group of young post-doctoral researchers, closely cooperating on the projects with researchers from industrial companies from all over Europe, became one of the two pillars of the newly established Department of Functional Materials in 2000, currently led by Šittner.
Petr Šittner is also involved with the development of new neutron diffraction and imagining methods within the Czech part of project to build the European Spallation Source in Lund, Sweden. In the last twenty years, he has been involved in several short-term assignments at the Mie University in Japan, University of Western Australia in Perth or Université Franche-Comté in Besancon and Université Joseph Furrier in Grenoble (both in France) as a visiting professor.
Praemium Academiae
The decision to award the Academy Premium is taken by the president of the Czech Academy of Sciences in consultation with the Advisory Board composed of Czech and international experts based on the results achieved by researchers and considering the future perspective of their research. Apart from expert CVs and a framework intent presenting the main focus of the research, the selected candidates are asked to submit a schedule for drawing the funds. At the same time, the winners of the prize receive the status of a visitor of the Academic Assembly of the Czech Academy of Sciences for the duration of the funding programme. The proposals to award the Academy Premium are submitted by the Directors of individual institutes of the Czech Academy of Sciences and by the President of the Research Council of the Academy. Since 2007, the Academy Premium has been awarded to 29 researchers; the laureates include our colleagues: Pavel Jelínek (2016), Martin Nikl (2013), Tomáš Jungwirth (2008), Václav Petříček (2007).