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Department for Low Temperature Structure
Studies of Solids
Department
Head:
DrSci,
Associate Member of NASU, Professor
Mikhail
STRZHEMECHNY
tel: +(380)-57-340-91-83
E-mail:
strzhemechny@ilt.kharkov.ua
The Department was organized in 1990 by
amalgamating the former Laboratory of Structure-Sensitive Properties
of Solids and the Single-crystal x-ray Group from the Biophysics
Department. The old Laboratory was headed
by L. M. Polyakov (from 1962 till 1964), D. N. Bolshutkin (from
1965 till 1970), I. N. Krupskii (from 1970 till 1986), M. A.
Strzhemechny (from 1986 till 1988), and A. I. Erenburg (from 1988
till 1990).
In 2006 the Department incorporated the
Laboratory Optics of Molecular Crystals, which was headed by Prof.
A.A. Avdeenko, which initiated a complex structure-optical studies
of novel materials, including the fullerites, both pure and doped
with gases, molecular (organic) crystals, etc.
At the beginning (from 1962 to 1966)
the main objects of investigation were plastic and strength
properties of cryocrystals, i.e., solids with low melting
temperatures as well other solids that required in situ
sample growing. By and by the main interests of the Department have
shifted to other problems of solid state physics, namely, the
structure and dynamics of the above listed solids. In addition, by
the beginning of the 90-ies the Department was involved in studies
of the structure and thermodynamics of pure and doped fullerite C60.
In the early 2000-ies investigations into the structure and
luminescence properties of bromo-substituted benzophenones have been
initiated.
At present (June 2015) Department staff
includes 13 researchers and 2 PhD students, among them two Doctors
of Science (M. A. Strzhemechny and A.I. Prokhvatilov) as well as
nine PhD researchers: L.M. Buravtseva, V.V. Danchuk, P.V. Zinoviev,
V.N. Zoryanskii, N.V. Krainyukova, I.V. Legchenkova, O.S. Pyshkin,
A.A. Solodovnik, and Yu.E. Stetsenko.
Main scientific fields:
- structure of solids over a wide temperature range from liquid
helium to room temperature, using x-ray and electron diffraction;
- lattice dynamics of molecular crystals with account of internal
degrees of freedom;
- luminescence of molecular solids;
- phase transitions in solids;
- plasticity of cryocrystals.
Materials for investigation:
- cryocrytals, i.e. materials with low melting points, such as
rare gas solids, hydrogen, nitrogen, carbon oxide and monoxide,
nitrous oxide, methane, as well as binary alloys thereof;
- fullerenes and carbon nanotubes;
- molecular (organic) solids such various phenone derivatives, etc.;
- magnetically ordered materials,
The most important results obtained in
this Department:
- the extensive structure studies of the various molecular
cryocrystals and the orientational order therein, summarized in
four books:
Cryocrystals (eds. B. I. Verkin and A. F. Prikhot'ko)
Naukova Dumka, Kiev (1983) [in Russian].
Physics of Cryocrystals (eds. Yu. A. Freiman, V. G.
Manzhelii, M. L. Klein, and A. A. Maradudin) AIP Publishers, New
York (1996).
V.G.Manzhelii, A.I.Prokhvatilov, I.Ya. Minchina, and L.D.
Yantsevich. Handbook of Binary Solutions, Begell House
Inc., New York - Wallinford (1996).
V.G.Manzhelii,A.I.Prokhvatilov, V.G.Gavrilko, A.P.Isakina.
Handbook of Structure and Thermodynamic Properties of Cryocrystals.
Begell House Inc., New York - Wallinford (1997).
- determination of the structure of many molecular solids such as
caffeine, adenine, theofiline, and other.
- the first results on the plasticity characteristics of many
cryocrystals, including the quantum crystal of hydrogen and solid
nitrogen
- x-ray and electron diffraction determination of the structure of
various cryoalloy systems such as solid mixtures of simplest
molecular components (nitrogen, carbon dioxide and monoxide,
methanes, etc.) and rare gases with an eye for studying the
molecular glass aspects.
- combined structure-luminescence studies of fullerite C60
saturated with gases, which allowed not only the observation of the
strong dependence of the orientational glassification point Tg
on saturation but also explanation of the effect of the sharp
decrease of lamination intensities upon crossing Tg;
- explanation of the huge (by a factor of 106)
acceleration of the conversion in solid hydrogen at very high
pressures;
- observation and explanation of the cardinal changes of the
luminescence of ortho-bromobenzophenone crystal and glass with
temperature;
- growth of two polymorphs of para-bromobenzophenones and the
comparative study concerning the triplet exciton dynamics in the two
polymorphs.
The Department has experimental setups
and the respective measurement procedures, originally developed and
successfully run for years, among which are:
- liquid-helium powder x-ray cryostat operating from 2 K to room
temperature;
- liquid-helium cryostat for electron diffraction studies from 2 K
to room temperature;
- setup for studies of spectral luminescence properties of emitters
with low quantum output, working over a wide temperature range (10
to 300 K);
- setup for measuring integrated and microsecond time-resolved
luminescence spectra as well as relative quantum gain of molecular
crystals in the temperature range from 1.6 to 300K. |