Inhomogeneous magnetic phase in Co-Al-O spinet nanocrystals

被引：3

作者：

Sato, K. ^{[1
]}

Naka, T. ^{[1
]}

Nakane, T. ^{[1
]}

Rangappa, D. ^{[2
]}

Takami, S. ^{[3
]}

Ohara, S. ^{[4
]}

Adschiri, T. ^{[5
]}

机构：

[1] Natl Inst Mat Sci, Tsukuba, Ibaraki 3050047, Japan

[2] Int Adv Res Ctr Powder Met & New Mat, Hyderabad 500005, Andhra Pradesh, India

[3] Tohoku Univ, Inst Multidisciplinary Res Adv Mat, Aoba Ku, Sendai, Miyagi 9808577, Japan

[4] Osaka Univ, Joining & Welding Res Inst, Osaka 5670047, Japan

[5] Tohoku Univ, Adv Inst Mat Res, WPI, Aoba Ku, Sendai, Miyagi 9808577, Japan

来源：

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS | 2014年 / 350卷

基金：

日本学术振兴会;

关键词：

Cobalt spinel; Nanocrystal; Crystal structure; Antiferromagnetism; GLASS BEHAVIOR; COAL2O4;

D O I：

10.1016/j.jmmm.2013.09.012

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We report on the crystallographic structure and magnetism of 5-nm Co-Al-O spinel nanocrystals synthesized under supercritical hydrothermal conditions. Structural examination using powder X-ray diffraction and chemical analysis showed the composition of the sample to be Co0.47Al2.36O4 rather than the stoichiometric composition of CoAl2O4. The site occupancy of Co on the A-site forming the diamond lattice was 0.47, which is slightly larger than the site percolation limit Magnetization measurements showed that magnetic clusters emerged below 40 K. At temperatures below 40 K, a Griffiths-phase-like inhomogeneous state appeared in the sample in which magnetic clusters and paramagnetic spins coexisted. The dc-paramagnetic and ac-susceptibilities exhibited an anomaly below 7 K. (C)) 2013 Elsevier B.V. All rights reserved.

引用

页码：161 / 166

页数：6

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