|
Delafossites are an interesting class of materials with unique magnetic and electric properties, which
classify them to employ in a wide range of important applications [1]. Due to their composition,
which is described by general formula ABO
2
(A = Cu, Ag, Pd, Pt; B = Fe, Co, Ni, Cr, etc.), they may
be insulators, semiconductors or conductors. A lot of them are also multiferroic materials [2].
Delafossites have two types of perovskite
-
like layered crystalline structure: rhombohedral
-
3R
(spac
e group
R
-
3m
) and hexagonal
–
2H
(space group
P6
3
/mmc
). One of the most interesting
phenomenon is weak ferromagnetism induced in delafossite structure by doping with transition
metals ions, e.g., CuCo
x
Cr
1
-
x
O
2
[3].
To our knowledge, there is lack of
experimental data available on the doped AgFeO
2
. Hence, the
main goal of the present work was to synthesize
AgCo
x
Fe
1
-
x
O
2
compounds and
recognize their
structure and magnetic properties.
To obtain the powder specimens with cobalt concentration up to
x = 0.2
a simple co
-
precipitation method was employed. The prepared samples were examined using
X
-
ray diffraction (XRD) and
57
Fe Mössbauer spectroscopy at room temperature. The structural and
hyperfine interactions parameters were recognized in connection with in
creasing cobalt
concentration. Despite of detecting traces of metallic silver in XRD patterns, there are no peaks
indicated Co
2
O
3
, Fe
2
O
3
and spinel
-
CoFe
2
O
4
phases, which readily form in the conditions similar to
synthesis of AgFeO
2
. Therefore, it was rev
ealed that delafossite structure is maintained, and
considered that substitution of Fe ions by Co ions in silver ferrite structure is possible.
|
