Anomalous magnetic properties of MnO nanoclusters.
In this communication, we experimentally report, for the first time, that the MnO nanoclusters with cluster diameters of 5-10 nm show a ferromagnetic behavior with a phase transition from ferromagnetic to paramagnetic phases at 27 K even though their bulk phase is antiferromagnetic. We observed large coercivities up to 9500 Oe and a large remanence of 1.72 emu/g at 2 K, which are typically observed values for ferromagnetic materials. Although it is not clear, this abnormal ferromagnetic behavior of MnO nanoclusters may arise from cluster size effects.
Lee
Gang H
GH
Department of Chemistry, College of Natural Sciences, Kyungpook National University, Taegu 702-701, South Korea. ghlee@bh.knu.ac.kr
Huh
Seung H
SH
Jeong
Jin W
JW
Choi
Byeong J
BJ
Kim
Seung H
SH
Ri
Hyeong-C
HC