Link to:

Scientific interests:

They
are related to Surface Science and to the experimental studies using mainly the methods of High-resolution electron-energy loss spectroscopy (HREELS), X-Ray photoelectron spectroscopy (XPS), Low-energy electron diffraction (LEED):

• Study of the local structure of some adsorbates (ethylene, acetylene, oxygen, CO, NO) on monocrystalline surfaces such as Ir(111), Ru(0001), Si(100)-(2×1), Pt(111).
• Study of the dynamics of solid surfaces; determination of the dispersions of adsorbate vibrations and of surface phonons. 
• Synchrotron measurements of the charge transfer time from some adsorbates to the adsorbent surfaces.
• Study of the surface phonon modes and their dispersion of well-ordered thin films (NiO, MnO) on monocrystalline  surfaces such as Ag(100), Ni(100), Pt(111). 
• Study of the binding-energy change of core-level electrons of the surface atoms due to some surface interactions.

Selected papers:

1. S. Lizzit, R. Larciprete, P. Lacovig, K.L. Kostov, D. Menzel,
   Ultrafast Charge Transfer at Monolayer Graphene Surfaces with Varied Substrate Coupling,
    ACS Nano, 7 (5), 2013, pp 4359–4366.
2. K.L. Kostov, S. Polzin, S.K. Saha, O. Brovko, V. Stepanyuk, W. Widdra,
   Германия Surface-phonon dispersion of a NiO(100) thin film,
   Physical Review B  87 (23), 2013, Art.  Number: 235416
3. A. Sachse, V. Hulea, K.L. Kostov, E. Belamie,  B. Alonso,
   Improved silica-titania catalysts by chitin bio-templating,
   Catal. Sci. Technol., 2015, 5, 415-427. 
4. K. L. Kostov, F. O. Schumann, S. Polzin, D. Sander, and W. Widdra,
   NiO growth on Ag(001): A layer-by-layer vibrational study,
   Physical Review B 94 (2016) Art. Num. 075438,
5. M. Milanova, K.L. Kostov, R. Iordanova , L. Aleksandrov , A. Yordanova, T. Mineva,  
   Local structure, connectivity and physical properties of glasses in the B₂O₃– Bi₂O₃-La₂O₃-WO₃ system,
   Journal of Non-Crystalline Solids 516 (2019) pp.35-44

International
cooperation:

• 1990-2004  with Prof. Dr. Dietrich Menzel on the subject „Adsorption on solid surfaces: microscopic analysis of states and processes. Sub-project: Vibrational properties of surfaces and adsorbates „.
• 2001-2013 Synchrotron studies with Prof. Dr. Dietrich Menzel and Dr. Silvano Lizzit: (a)“Ultrafast charge transfer at surfaces by Auger Resonant Raman spectroscopy: Dependence of time constants on coupling strength (long term project); (b)  “Adsorbate induced surface core level shifts: does the additivity rule hold also for coadsorbates?”; (c) “ Ultrafast charge transfer at surfaces and into layers: two- or three-dimensional final states?”.
• 2000- and now with Prof. Dr. Wolf Widdra at Martin-Luther-University-Halle / Wittenberg, on topics like: (a) Vibrational properties of thin transition-metal oxide films; (b) Functional-oxide surfaces: atomic structure and local electron-spectroscopy of complex oxide structures; (c) Stress and lattice dynamics in multiferroic systems.
• 2012- and now with Prof. Dr. Bruno Alonso, Prof. Dr. Emmanuell Belamie and Prof.Dr. Tzonka Mineva, Charles-Gerhard Institute, CNRS, Montpellier, France, on topics „Study of Biopolymer-Oxide Nanocomposites with the Methods of Photoelectron Spectroscopy and Nuclear Magnetic Resonance“.