ISSN 1063-7761, Journal of Experimental and Theoretical Physics, 2013, Vol. 117, No. 5, pp. 879–884. © Pleiades Publishing, Inc., 2013.
Original Russian Text © A.M. Vorotynov, G.M. Abramova, A.I. Panktats, G.A. Petrakovskii, S.M. Zharkov, G.M. Zeer, V.I. Tugarinov, M.V. Rautskii, V.V. Sokolov, 2013, published
in Zhurnal Eksperimental’noi i Teoreticheskoi Fiziki, 2013, Vol. 144, No. 5, pp. 1009–1015.
879
1. INTRODUCTION
The search for and investigation of new materials
with special magnetic and electric properties are
among the priority directions of development of mag-
netism and solid-state physics. The experimental
results accumulated to date lead to the conclusion that
the interrelation of magnetic and electric properties is
most pronounced in “layered” structures that are an
alternation of anion and cation planes. Such a crystal-
line structure is characteristic of 3d-metal monosul-
fides and disulfides [1, 2].
Layered copper–chromium disulfide (CuCrS
2
) is
known to be an antiferromagnet with a Neel tempera-
ture T
N
= 40 K that has an alignment of magnetic
moments similar to manganites, europium and man-
ganese chalcogenides. The rhombohedral lattice of
copper–chromium disulfide (structural type
α-NaFeO
2
) is a derivative of the NaCl structure and
has space group R3m [3]. Particular interest in CuCrS
2
stems from the fact that this compound belongs to lay-
ered intercalated materials, in which the weak (Van der
Waals) bond, along with the ion–covalent bonds, plays
an important role [1, 3]. The CuCrS
2
compound is
considered [4] as a quasi-two-dimensional antiferro-
magnet whose magnetic properties are determined by
the ferromagnetic alignment of the magnetic moments
of trivalent chromium ions in the alternating triple
CrS
2
layers and by their antiferromagnetic alignment
between the CrS
2
–Cu–CrS
2
layers. As further studies
showed [5], the magnetic structure of CuCrS
2
turned
out to be more complex than was assumed in the first
works.
CuCrS
2
is a paramagnetic electron–ion semicon-
ductor at room temperature and undergoes a superi-
onic conductor–semiconductor transition at 670 K
[6], an electronic transition at 110 K [7], and a transi-
tion to an antiferromagnetic state at 37 K [8, 9].
Quasi-two-dimensional layered structures that are
three-dimensional crystals with a strong anisotropy of
chemical bonds can be promising matrices for the pro-
duction of new multilayered materials. Multilayered
(magnetic/nonmagnetic, insulator/metal) structures
can be produced by using various crystal growth tech-
nologies. Previously [10], it has been established that
the physical properties of copper–chromium disulfide
depend significantly on the sample preparation tech-
nology. In particular, the polycrystalline samples are
single-phase ones and have a rhombohedral structure
typical of CuCrS
2
, while the single crystals [11] can
contain an additional spinel phase (CuCr
2
S
4
).
In this paper, we present the results of our study of
the magnetic resonance for samples composed of sin-
gle-crystal CuCrS
2
layers (planes) and thin CuCr
2
S
4
plates.
2. SAMPLE PREPARATION
AND CHARACTERISTICS
Single crystals were synthesized from a polycrystal-
line CuCrS
2
powder whose X-ray diffractogram is pre-
sented in Fig. 1 in comparison with the X-ray diffrac-
togram from the structural data bank.
The crystalline structure of polycrystals corre-
sponds to the published data for CuCrS
2
. The rhom-
bohedral lattice parameters (space group R3m) are a =
3.485 Å and c = 18.70 Å. No accompanying phases
were detected within the error limits of the method.
We used the method of chemical transport reac-
tions to grow CuCrS
2
single crystals and iodine as a
Magnetic Resonance in a Cu–Cr–S Structure
A. M. Vorotynov
a,
*, G. M. Abramova
a
, A. I. Panktats
a,b
, G. A. Petrakovskii
a
, S. M. Zharkov
a,b
,
G. M. Zeer
b
, V. I. Tugarinov
a
, M. V. Rautskii
a
, and V. V. Sokolov
c
a
Kirensky Institute of Physics, Russian Academy of Sciences, Siberian Branch, Krasnoyarsk, 660036 Russia
b
Siberian Federal University, Krasnoyarsk, 660041 Russia
c
Nikolaev Institute of Inorganic Chemistry, Russian Academy of Sciences, Siberian Branch, Novosibirsk, 630090 Russia
*E-mail: sasa@iph.krasn.ru
Received April 29, 2013
Abstract—A layered Cu–Cr–S structure composed of single-crystal CuCrS
2
layers and thin CuCr
2
S
4
plates
embedded in them has been investigated by the magnetic resonance and scanning electron microscopy meth-
ods. The Curie temperature and saturation magnetization of the spinel phase of the investigated samples have
been determined. The thickness of the CuCr
2
S
4
layers has been estimated. The dependence of the grown-
crystal topology on synthesis conditions has been established. An interpretation of the anomalous behavior of
the magnetostatic oscillation intensity is offered.
DOI: 10.1134/S1063776113130189
ORDER, DISORDER, AND PHASE TRANSITION
IN CONDENSED SYSTEM