Computational Surface Science Group

We use computer simulations to study surface processes at the atomic level, stimulated by impacts of energetic projectiles in the 3- (3D) and 2-dimensional (2D) systems.

The rapid progress of miniaturization, which has taken place in recent years, has sparked a great deal of interest in the study of physical and chemical phenomena occurring in devices with dimensions not much larger than the dimensions of individual atoms. This interest resulted in a quest for experimental techniques that would make it possible to measure the chemical composition on this scale. Examples of such techniques are Secondary Ion Mass Spectrometry (SIMS) and Secondary Neutral Mass Spectrometry (SNMS). They are so sensitive that they can find a single atom or molecule hidden among billions of other atoms.

SIMS and SNMS have numerous practical applications. They are used in the design and control of integrated circuits or OLEDs that drive our electronic devices. They are also used to determine the age of geological structures, perform forgery check of paintings and sculptures, or help to catch criminals based on evidence found at a crime scene. However, the most fascinating application of SIMS/SNMS is its use in medical research and diagnostics. For example, these techniques create three-dimensional chemical images of biological cells. They play a vital role in the development of new drugs. Compact and fully automatic SIMS systems are introduced into hospital operating rooms, where they support surgical procedures in the rapid identification of malignant tumor tissues. Currently, such identification can take days, and if the diagnosis is inauspicious, the patient must go through surgery again.

The primary objective of our research is to provide a theoretical background, explanation, and verification of recent findings and hypotheses, which emerge, as SIMS and SNMS expand beyond their current frontiers. State of the art computer simulations are used to study physicochemical processes emerging in new analytical configurations based on cluster projectiles and 2-dimensional and liquid supports. Research on liquid supports is particularly essential, as water is the main component of our body. It is crucial, therefore, to understand what is happening in such an environment.

Visualization of the cluster projectiles and organic molecules being investigated in our group recently.
Schematic showing the preparation of a vacuum-compatible device for 3D molecular imaging of liquid samples using ToF-SIMS.
Group members
  • Prof. Zbigniew Postawa - Head
  • Mikołaj Gołuński
  • Sviatoslav Hrabar
  • Michał Kański
  • Dawid Maciążek
Equipment and Methodology

We use our computing server equipped with 356 computing units and the PLGrid supercomputer network, where we have a grant for 8,000,000 computing hours for a maximum of 5,000 computing units.

Molecular Dynamics computer simulations are used to probe and visualize investigated phenomena. Since the dawn of computer technology, computer simulations have established themselves as an essential theoretical partner to experimental measurements. If a new phenomenon is observed, one is usually trying to find general trends that may occur in the data by systematically modifying the initial parameters of the probed system. This task can be accomplished by both experimental measurements and computer modeling. Actually, a successful comparison between the experimental and theoretical observations is usually an essential step in establishing the credibility of the computer model. In the next step, we typically want to understand which processes are responsible for these trends to occur. Computer simulations are particularly well suited to pursue this goal as they allow to probe a number of properties that cannot be directly measured in the experiment. For instance, they allow to visually inspect the atomic motions leading to any particular event or sets of events. It is the correlation of the microscopic basis of atomic motions with experimental data that, in our opinion, is the real strength of the MD simulations as a partner to SIMS experiments.

Research Projects
  • Sputtering and modification of 2D systems (graphene, h-BN, MoS2)
  • Bombardment of liquid matrices with cluster projectiles
  • Computer modeling of depth profiling phenomena
  • Cluster bombardments of solid surfaces
  • Development of Reax-type many body potentials
Our Research Advertised at the Journal Frontpages
Collaborators
  • Gerhard Hobler, TU Wien, Austria
  • Emile Schweikert, The Texas A&M University, USA
  • Stanislav Verkhoturov, The Texas A&M University, USA
  • Nicholas Winograd, The Pennsylvania State University, USA
Contact
prof. dr hab. Zbigniew Postawa
room: B-1-17
phone: 12 664 46 26
email: zbigniew.postawa@uj.edu.pl

More can be found on the group website at the Group page.