https://doi.org/10.1007/s100510050298
Structure, composition and magnetocaloric properties in polycrystalline La 1-x A x MnO 3+8 (A = Na, K)
1
National Laboratory of Solid State Microstructures, Nanjing University,
Nanjing 210093, P.R. China
2
Department of Chemistry, Nanjing University, Nanjing 210093, P.R. China
3
Department of Physics, Hebei Normal University, Shijiazhuang 050091, P.
R. China
Corresponding author: a ufp@netra.nju.edu.cn
Received:
12
September
1997
Revised:
18
December
1997
Accepted:
21
January
1998
Published online: 15 May 1998
The polycrystalline perovskitelike manganese oxides LaAxMnO
(A = Na, and K,
) have been fabricated by
sol-gel technique. For all the compositions explored in this work, the
average manganese oxidation state is practically constant, at
for A = Na, and
for A = K, respectively. A close relationship is
confirmed to hold between the Curie temperature (Tc) and the bond distance
of Mn-O. Results of magnetic measurements show that these materials can be
utilized as suitable candidates for magnetic refrigerants with wide applied
temperature span, for their significant entropy change and the easily tuned
Curie temperature.
PACS: 75.30.Sg – Magnetocaloric effect / 82.80.-d – Chemical analysis and related physical methods of analysis / 81.05.Mh – Cermets, ceramic and refractory composites
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1998