Prof. Alexander V. Soldatov [Lulea University of Technology, Sweden]

Title: Carbon nanotubes under high dynamic and static compression: structural integrity limits and beyond

Time: 10:00 - 11:00 AM, Thursday, September 14, 2017

Place: Conference room 410, HPSTAR (Shanghai)

Host: Ho-Kwang Mao

Abstract

We report on a systematic study of carbon nanotubes (CNTs) with different morphology (single (SW)- and double-walled(DW)) exposed to dynamic (shock-wave) and static compression. The dynamic compression experiments were conducted in a recovery assembly: the load was ramped at pressures in the range 19 - 52 GPa with each time a new CNT sample but from the same source batch whereas the experiment at static pressure up to 58 GPa was done in a diamond anvil cell (DAC). The recovered samples were characterized by Raman and high-resolution transmission electron microscopy. After exposure to 19 GPa of dynamic compression the CNT material exhibited substantial structural damage such as CNT wall disruption, opening of the nanotube along the tube axis (“unzipping”) and ”chopping“ (shortening) of the tubes. Remarkably, ramping shock pressure to 36 GPa resulted in essentially complete SWCNT destruction whereas at least a fraction of the nanotubes was recovered after 35 GPa of static compression though severely damaged. The limit of structural integrity of the SWCNTs at static pressure was established in the DAC at 58 GPa. Along with the nature of the applied pressure, we discuss other possible reasons which may have caused such effect and compare our data with the results obtained on shocked double DWCNTs.

Biography of the Speaker:





Prof. Alex Soldatov focuses his research on synthesis and characterization of novel carbon-based materials and disordered systems from nanostructured carbon precursors (fullerenes, nanotubes, graphene) using high pressure and high temperature. He has background and expertise in low temperature and high pressure experiment and actively uses synchrotron and  neutron spallation sources in his research. He received his MS in engineering physics from Kharkov Polytechnic University, Ukraine in 1984 and PhD in low temperature physics from the Institute for Low Temperature Physics & Engineering, Ukrainian Academy of Sciences in 1995. Thereafter he took during 1995-99 postdoc positions in Umea university, Sweden, University of Sussex, UK and Research Centre Karlsruhe, Germany before joining Prof. Silvera group at the Department of Physics, Harvard university as a research associate in 1999. In 2002 he moved back to Europe to take a full faculty position at Dept. of Applied Physics and Mechanical Engineering, Lulea university of technology, Sweden and he is also affiliated with the Dept. of Physics, Harvard.  

Prof. Soldatov is recipient of Shubnikov Prize for research on thermal properties of Hydrogens and low temperatures. He was Royal Society/NATO visiting scholar at University of Sussex and was awarded number of times visiting professor scholarships in Lyon and Nancy university and Karlsruhe Institute of Technology. His publication record includes Science, Nano Letters, Nanoscale, PRL, PRB, etc. He is regularly invited to speak at major international conferences in the field.

Prof. Soldatov served several times as European High Pressure Research Group (EHPRG) Committee member and since 2015 he is elected member of the Executive Committee of the AIRAPT. He is a member of the Swedish Universities Reference/Advisory Group on MAX IV Synchrotron Radiation Facility in Sweden

The other areas of Prof. Soldatov research interest include molecular electronics devices, sensors, quantum phenomena in molecular nanostructures, single molecule spectroscopy, tribo-chemistry/physics.

=====================

More talks are scheduled on:

September 21 (10:00 - 11:00)