Junior Research Group of Dr. Svetoslav Stankov

 

Nanodynamics is a Helmholtz-University Young Investigators Group with a subject “Interplay between structure and lattice dynamics of epitaxial rare earth nanostructures”. The group is established jointly by the Institute for Synchrotron Radiation (Campus Nord) and by the Laboratory for Applications of Synchrotron Radiation (Campus Süd) of the Karlsruhe Institute of Technology.

Our efforts are focused on growth and systematic investigation of the influence of structure, size, strain, and shape on the lattice dynamics, thermodynamic, and elastic properties of epitaxial rare earth based nanostructures.
This research is motivated by the observed significant modification of the lattice dynamics of the nanoscale materials in comparison to the bulk counterparts. It is expected that the thermal lattice excitations (phonons) will play an important role for the performance, lifetime, and thermodynamic stability of the near-future nanodevices. Therefore, for nanotechnological applications it is mandatory to get fundamental and comprehensive understanding of the lattice dynamics in order to better control and even tailor thermal and elastic properties at the nanoscale.
Nanostructures based on the rare earth elements play an important role in various fields such as micro and nano electronics, catalysis, and magnetism. Particularly important are the thin rare earth oxide films selected to replace SiO2 in the CMOS technology due to their high dielectric constants (high-k materials). This allows one to push the sizes of the devices to ever smaller dimensions.

In our research we combine state of the art surface science techniques with in-situ synchrotron radiation scattering and spectroscopic methods at large scale facilities such as ANKA (Karlsruhe), ESRF (Grenoble), and PETRA III (Hamburg).
 

Junior Research Group of Dr. Svetoslav Stankov

 

Papers published in refereed journals

 

Vibrational thermodynamics of Fe₉₀Zr₇B₃ nanocrystalline

alloy from nuclear inelastic scattering

S. Stankov, M. Miglierini, A. I. Chumakov, I. Sergueev, Y. Z. Yue, B. Sepiol, P. Svec,

L. Hu, R. Rüffer

Phys. Rev. B 82, 144301 (2010)

 

Noncollinear Magnetization Structure at the Thickness-Driven Spin-Reorientation Transition in Epitaxial Fe Films on W(110)

T. Slezak, M. Slezak, M. Zajac K. Freindl, A. Koziol-Rachwal, K. Matlak, N. Spiridis, D. Wilgocka-Slezak, E. Partyka-Jankowska, M. Rennhofer, A. I. Chumakov, S. Stankov, R. Rüffer, J. Korecki

Phys. Phys. Lett. 105, 027206 (2010)

 

Vibrational properties of alpha- and sigma-phase Fe-Cr alloy
S. M. Dubiel, J. Cieslak, W. Sturhahn, M. Sternik, P. Piekarz, S. Stankov, K. Parlinski
Phys. Phys. Lett. 104, 155503 (2010)

 

Phonons in iron monolayers
S. Stankov, M. Sladecek, T. Slezak, J Lazewski, R. Röhlsberger, B. Sepiol, G. Vogl, A. I. Chumakov, R. Rüffer, N. Spiridis, M. Zajac, M. Slezak, K. Parlinski, J. Korecki
J. Phys.: Conf. Ser. 217, 012144 (2010)

 

Magnetism of ultra-thin iron films seen by the nuclear resonant scattering of
synchrotron radiation
T. Slezak, K. Freindl, A. Koziol-Rachwal, K. Matlak, M. Rennhofer, R. Rüffer, B. Sepiol, N. Spiridis, S. Stankov, D. Wilgocka-Slezak, M. Zajac, J. Korecki
J. Phys.:Conf. Ser. 217, 012090 (2010)

 

Isotope-periodic multilayer method for self-diffusion paths-a comparative neutron and synchrotron Mössbauer reflectrometric study of FePd alloys

D. Merkel, S. Sajti, J., Major, R. Rüffer, A. Rühm, S. Stankov, F. Tancziko, L. Bottyan

J. Phys.:Conf. Ser. 211, 0120291 (2010)

Stabilization of Antiferromagnetic Order in FeO Nanolayers
S. Couet, K. Schlage, R, Rüffer, S. Stankov, Th. Diederich, B. Laenens, and R. Röhlsberger
Phys. Phys. Lett. 103, 097201 (2009)

Probing correlations in magnetic layer systems via multiple isotopic sensor layers
S. Couet, Th. Diederich, S. Stankov, K. Schlage, T. Slezak, R. Rüffer, J. Korecki, and R. Röhlsberger
Appl. Phys. Lett. 94, 162501 (2009)

Determination of the Mössbauer Parameters of Rare–Earth Nitroprussides: Evidence for new Light Induced Magnetic Excited State (LIMES) in Nitroprussides
V. Rusanov, S. Stankov, A. Ahmedova, and A. X. Trautwein
J. Solid State Chem. 182, 1252 (2009)

Lattice dynamics of europium from nuclear inelastic scattering and first principle calculations
S. Stankov, P. Piekarz, K. Parlinski, A. M. Oles, and R. Rüffer
Phys. Rev. B 78, 180301(R) (2008)

Vibrational Properties of Nanograins and Interfaces in Nanocrystalline Materials
S. Stankov, Y. Z. Yue, M. Miglierini, B. Sepiol, I. Sergueev, A. I. Chumakov, L. Hu, P. Svec, and R. Rüffer
Phys. Rev. Lett. 100, 235503 (2008)

An Ultrahigh Vacuum System for in–situ Study of Thin Films and Nanostructures by Nuclear Resonance Scattering of Synchrotron Radiation
S. Stankov, R. Rüffer, M. Sladecek, M. Rennhofer, B. Sepiol, G. Vogl, N. Spiridis, T. Slęzak, and J. Korecki
Rev. Sci. Instr. 79, 045108 (2008)

Modification of local order in FePd films by low energy He+ irradiation
D. G. Merkel, M. Major, A. Nemeth, Sz. Sajti, F. Tancziko, L. Bottyan, Z. E. Horvath, J. Waizinger, S. Stankov, R. Rüffer, A. Kovacs
J. Appl. Phys. 104, 013901 (2008)

Influence of Dynamic Effects in Nuclear Resonant Bragg Scattering on the Accuracy of Determination of Self–Diffusion Coefficient in Fe/Fe Periodic Multilayers
M. A. Andreeva, N. G. Monina, and S. Stankov
Moscow Univ. Phys. Bull. 63/2,132 (2008)

Nuclear Resonant Scattering Studies of Electric Field Gradient in Fe-Monolayers on W(110)
E. Partyka-Jankowska, B. Sepiol, M. Sladecek, D. Kmiec, J. Korecki, T. Slezak, M. Zajac, S. Stankov, R. Rüffer, and G. Vogl
Surf. Sci. 602, 1453 (2008)

He+ ion irradiation–induced disordering in L10–FePd thin films: Ion fluence dependence
A. Kovács, D. G. Merkel, F. Tanczikó, S. Stankov, Y. Hirotsu, L. Bottyán
Scripta Mater. 58, 635 (2008)

Magnetism of Ultrathin Films Seen by Nuclear Resonance Scattering of Synchrotron Radiation
T. Slezak, S. Stankov, M. Zajac, M. Slezak, K. Matlak, N. Spiridis, B. Laenens, N. Planckaert, M. Rennhofer, K. Freindl, D. Wilgocka-Slezak, R. Rüffer, and J. Korecki
Mater. Sci. (Poland) 26/4, 885 (2008)

Phonons in Iron: From the Bulk to an Epitaxial Monolayer
S. Stankov, R. Röhlsberger, T. Slezak, M. Sladecek, B. Sepiol, G. Vogl, A. I. Chumakov, R. Rüffer, N. Spiridis, J. Lazewski, K. Parlinski, and J. Korecki
Phys. Rev. Lett. 99, 185501 (2007)

Phonons at the Fe(110) Surface
T. Slezak, J. Lazewski, S. Stankov, K. Parlinski, R. Reitinger, M. Rennhofer, R. Rüffer, B. Sepiol, M. Slezak, N. Spiridis, M. Zajac, A. I. Chumakov, and J. Korecki
Phys. Rev. Lett. 99, 066103 (2007)

Surface Diffusion and Island Growth
R. Reitinger, B. Pfau, L.-M. Stadler, S. Stankov, M. Zajac, N. Spiridis, B. Sepiol, F. Zontone, and J. Korecki
Defect and Diffusion Forum 262, 177 (2007)

Morphology of Fe/MgO(001) ultrathin films
R. Reitinger, B. Sepiol, G. Vogl, B. Pfau, L.-M. Stadler, S. Stankov, F. Zontone, N. Spiridis, and J. Korecki
J. Appl. Phys. 102, 034310 (2007)

Depth dependence of iron diffusion in Fe3Si studied with nuclear resonant scattering
D. Kmiec, B. Sepiol, M. Sladecek, M. Rennhofer, S. Stankov, G. Vogl, B. Laenens, J. Meersschaut, T. Slezak, and M. Zajac
Phys. Rev. B 75, 054306 (2007)

Self–diffusion of iron in L10 ordered FePt thin films
M. Rennhofer, B. Sepiol, M. Sladecek, D. Kmiec, S. Stankov, G. Vogl, M. Kozlowski, R. Kozubski, A. Vantomme, J. Meersschaut, R. Rüffer, and A. Gupta
Phys. Rev. B 74, 104301 (2006)

Determination of Lamb–Mössbauer Factors and Lattice Dynamics in Some Nitroprusside Single Crystals
V. Rusanov, S. Stankov, V. Gushterov, L. Tsankov, A. X. Trautwein
Hyperfine Interact. 169, 1279 (2006)

Dynamics in FePt Thin Films Studied by Grazing Incidence Synchrotron Reflection on Izotopic Multilayers
M. Rennhofer, M. Sladecek, D. Kmiec, S. Stankov, B. Sepiol, G. Vogl, R. Rüffer, A. Vantomme, J. Meersschaut
Diffusion Fundamentals 2, 58 (2005)

High Temperature Mössbauer Effect Study of Fe90Zr7B3 Nanocrystalline Alloy
S. Stankov, B. Sepiol, T. Kanuch, D. Scherjau, R. Würschum, M. Miglierini
J. Phys.: Cond. Matter 17, 3183 (2005)

On the Theory of the Coherence and Polarization Effects and Angle–Dependent Mössbauer Spectroscopy on Nitroprusside Single Crystals
V. Rusanov, S. Stankov, V. Angelov, N. Koop, H. Winkler, A. X. Trautwein
Nucl. Instr. and Meth. B 207/2, 205 (2003)

Catalysts for the Oxygen Reduction from Heat–Treated Iron (III) Tetramethoxyphenylporphyrin Chloride: Structure and Stability of Active Sites
H. Schulenburg, S. Stankov, V. Schünemann, J. Radnik, I. Dorbandt, S. Fiechter, P. Bogdanoff, H. Tributsch
J. Phys. Chem. B 107, 9034 (2003)

Mössbauer Investigations of the Single Crystal and Powder Sample of Barium Nitroprusside   (BNP)
S. Stankov, V. Rusanov, V. Angelov, S. Haussühl, A. X. Trautwein
Hyperfine Interact. 141/142, 223 (2002)

Photoswitching of Nitroprussides
V. Rusanov, S. Stankov, A. X. Trautwein
Hyperfine Interact. 144, 307 (2002)

Line Width of Single–Crystal Mössbauer absorption
V. Rusanov, S. Stankov, V. Angelov, V. Schünemann
Nucl. Instr. and Meth. B 170, 443 (2000)

Invited contributions

Stabilization of magnetism in ultrathin iron oxide layers
S. Couet, K. Schlage, R. Rüffer, S. Stankov, Th. Diederich. B. Laenens, R. Röhlsberger
ESRF Highlights 2009, p. 13

Vibrational properties of nanograins and interfaces in nanocrystalline materials
S. Stankov, Y. Z. Yue, M. Miglierini, B. Sepiol, I. Sergueev, A. I. Chumakov, L. Hu, P. Svec, and R. Rüffer
ESRF Highlights 2008, p. 14

Phonons at the Fe (110) surface
T. Slezak, J. Lazewski, S. Stankov, K. Parlinski, R. Reitinger, M. Rennhofer, R. Rüffer, B. Sepiol, M. Slezak, N. Spiridis, M. Zajac, A. I. Chumakov, and J. Korecki
ESRF Highlights 2007, p. 14

Phonons in iron: from the bulk to a strained epitaxial monolayer
S. Stankov, R. Röhlsberger, T. Slezak, M. Sladecek, B. Sepiol, G. Vogl, A. I. Chumakov, R. Rüffer, N. Spiridis, J. Lazewski, K. Parlinski, and J. Korecki
ESRF Highlights 2006, p. 9