Yoed Tsur Yoed Tsur
Lab Head








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Research Interests
  • Synthesis and development of oxide materials for nanotechnology
  • Agglomeration strength of nano-powders
  • Point defect chemistry
  • Electroceramics and electroceramic devices
  • Impedance measurements and analysis
  • Detection and analysis of out-of-range phenomena and ill-posed inverse problems
  • Sustainable Energy

Some Examples of our research are explained Below:
Defect chemistry of perovskites Here we were involved in understanding the role of metal vacancies in barium titanate and revisiting accordingly the subject of defect chemistry of barium titanate and similar materials. We were also involved in finding the trends of site occupancy of trivalent dopants in barium titanate, and explaining the role of some of these dopants in life-time improvement of capacitors. We have demonstrated the importance of oxygen activity in the very early sintering of nanopowders.


Impedance spectroscopy measurements and other ill-posed inverse problems One of our main tools for analyzing electrical properties is impedance spectroscopy. The analysis of impedance spectroscopy data is an ill-posed inverse problem. We have developed not only experimental setup but also a new approach for dealing with the data, taking advantage of the pre-knowledge about the system. We are currently applying genetic algorithms to improve the analysis of such problems.
We have applied our new approach to analysis of other inverse problems, notably scatterometry of deep UV light for line edge roughness detection. This was done in cooperation with Nova Ltd. Our new approach makes it possible to put a relatively cheap machine in-line and detect all the wafers at a rate of seconds per wafer.


Synthesis of nano-ceramic materials We learn and develop synthesis routes to obtain and stabilize nanopowders, in particular of ceramic materials. This includes hydrothermal synthesis of barium titanate (pure and doped); hydrolysis of titania and titania-niobia solid solutions; hydrolysis of zinc peroxide nanoparticles and production of zinc oxide nanoparticles; combustion synthesis of perovskites and of silver embedded in carbon nanoparticles. It is important to produce the nanopowders that we investigate in our lab, since nanopowders are typically systems that are not in thermodynamic equilibrium, and hence their properties are strongly influenced by the synthesis route, on which we would like to have control. Great deal of our efforts in this area is directed to the development of simple, inexpensive and preferably water based routes. We now use nanopowder of barium titanate that we synthesize and stabilize in our lab to create thin films of sintered barium titanate on Ni electrodes by cathodic water-based electrophoretic deposition. This may open a new way to prepare complex shapes of dielectric material on a cheap electrode via environmentally benign route


Agglomeration
strength of nanomaterials 		One of the most important practical problems when dealing with nanopowders is its tendency to agglomerate. We are developing a new method to measure directly the agglomerate strength of nanomaterials. Individual agglomerates are fixed onto a hard substrate and their strength is measured by nanoindentation. We proposed that the agglomerate strength can be correlated with the shape of the nanoindentation load-displacement curves. This was already demonstrated on silver, barium titanate, ceria, titania and other nanopowders.


Technion Energy Program Prof. Tsur serves as a member in the Technion’s committee that is responsible to establish a coherent effort within the Technion in energy research and education. He is the coordinator of the fuel cells program, and a member in the graduate program committee.