Antiferromagnetic order in MnO spherical nanoparticles

被引：20

作者：

Wang, C. H. ^{[1
]}

Baker, S. N. ^{[1
]}

Lumsden, M. D. ^{[1
]}

Nagler, S. E. ^{[1
]}

Heller, W. T. ^{[1
]}

Baker, G. A. ^{[1
]}

Deen, P. D. ^{[2
]}

Cranswick, L. M. D. ^{[3
]}

Su, Y. ^{[4
]}

Christianson, A. D. ^{[1
]}

机构：

[1] Oak Ridge Natl Lab, Oak Ridge, TN 37831 USA

[2] Inst Max Von Laue Paul Langevin, F-38042 Grenoble 9, France

[3] Natl Res Council Canada, Chalk River Labs, Canadian Neutron Beam Ctr, Chalk River, ON K0J 1J0, Canada

[4] Forschungszentrum Julich, Outstn FRM 2, Julich Ctr Neutron Sci, D-85747 Garching, Germany

来源：

PHYSICAL REVIEW B | 2011年 / 83卷 / 21期

关键词：

MAGNETIC-PROPERTIES; ULTRAFINE-PARTICLE; NIO NANOPARTICLES; CLUSTERS; SIZE; TEMPERATURE; DEPENDENCE; TRANSITION;

D O I：

10.1103/PhysRevB.83.214418

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We have performed unpolarized and polarized neutron diffraction experiments on monodisperse 8- and 13-nm antiferromagnetic MnO nanoparticles. For the 8-nm sample, the antiferromagnetic transition temperature T-N (114 K) is suppressed compared to that in the bulk material (119 K), while for the 13-nm sample T-N (120 K) is comparable to that in the bulk. The neutron diffraction data of the nanoparticles is well described using the bulk MnO magnetic structure but with a substantially reduced average magnetic moment of 4.2 +/- 0.3 mu(B)/Mn for the 8-nm sample and 3.9 +/- 0.2 mu(B)/Mn for the 13-nm sample. An analysis of the polarized neutron data on both samples shows that in an individual MnO nanoparticle about 80% of Mn ions order. These results can be explained by a structure in which the monodisperse nanoparticles studied here have a core that behaves similar to the bulk with a surface layer which does not contribute significantly to the magnetic order.

引用

页数：7

共 37 条

[31] Magnetic property of antiferromagnetic MnO ultrafine-particle [J].