Assoc. Prof.
Education
M.S. Physics, Univ. of Sofia (1983)
Ph.D. Physics, Univ. of Sofia (1991)
Contact Information
232 Dow Hall, Dept. Physics
Phone: (989) 774-3395 Fax: (989)-774-2697
e-mail: petkov @ phy.cmich.edu
http://www.phy.cmich.edu/people/petkov/
Research Fields
Applied crystallography; x-ray (synchrotron) diffraction,
3D structure determination and modeling, magnetism
Current Research Projects
Properties of materials are predetermined
by the atomic-scale structure. For example, diamonds are
hard, transparent and expensive. Graphite is black, soft and
cheap. Both are pure carbon though; the difference comes from the
different arrangament of carbon atoms. It is a tetrahedral network in diamond and
a stack of hexagonal layers in graphite. Dr. Petkov's research aims at determining the 3D
atomic-scale structure of materials by x-ray diffraction and
computer simulations. Research is done at CMU
and synchrotron radiation
facilities. Mostly, a non-traditional experimental approach, that
of atomic pair distribution function analysis, is employed. Traditional crystallography (Rietveld) is done as well. Materials
of current interest include glasses (metallic, silicate, phosphate,
germanate, fast conductors), liquids (water),
polymers (dendrimers), composites (inorganic/organic),
nanoporous zeolites and carbons, ceramics (titanates,
zirconates), catalysts (Mo, Au and Pt based), nanoparticles (metallic
and inorganic), data storage media (optical: Ge-Sb-Te; magnetic:
Pt/Pd/Fe), disordered ferro and ferri magnets (transition & rare earth
metals based), and others. Funding
sources include NSF, DoE, ARL and CMU.
Selected Publications
V. Petkov et al "Atomic-scale structure of nanocrystals by
high-energy x-ray diffraction and atomic pair distribution function
analysis: study of Fe-Pd nanoparticles", J. Phys. Chem. C 111, 714 (2007).
V. Petkov et al "Atomic-scale structure of Ba/Sr-Ti-O ceramics"
Chem.
Mat. 18, 814 (2006).
V. Petkov et al "3D structure of gold nanopartciles in water by x-ray
diffraction and computer simulations" Phys. Rev. B 72 , 195402 (2005).
V. Petkov et al "3D structure of nanocomposites from atomic pair
distribution function analysis: study of polyaniline and PANI &
vanadium pentoxide", J. Am. Chem. Soc. 127,
8805 (2005).
V. Petkov et al "Structure beyond Bragg: study of vanadium pentoxide
nanotubes" Phys. Rev. B 69,
085410 (2004).
V. Petkov et al "Positional disorder of Ba in the thermoelectric
germanium clathrate: Ba6Ge25"
Solid. State Comm. 127, 43
(2003).
V. Petkov et al "Structure of intercalated Cs in zeolite ITQ-4:
an array of metal ions and correlated electrons confined in a pseudo-1D
host" Phys. Rev. Lett. 89,
075502 (2002).
All publications: http://www.phy.cmich.edu/people/petkov/list.html
Figure below: 3D structure (~9000 atoms) of a 7th generation PAMAM dendrimer used as
a template for nanosize objects
Source: V. Petkov et al "3D structure of dendrimers and
hyper-branched
macromolecules by x-ray diffraction" Solid. State Comm. 134, 671 (2005).