Absence of ferromagnetism in Co and Mn substituted polycrystalline ZnO

被引：419

作者：

Lawes, G

Risbud, AS

Ramirez, AP

Seshadri, R

机构：

[1] Los Alamos Natl Lab, Los Alamos, NM 87545 USA

[2] Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA

[3] Bell Labs, Lucent Technol, Murray Hill, NJ 07974 USA

[4] Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA

[5] Univ Calif Santa Barbara, Mat Res Lab, Santa Barbara, CA 93106 USA

来源：

PHYSICAL REVIEW B | 2005年 / 71卷 / 04期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1103/PhysRevB.71.045201

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We discuss the properties of semiconducting bulk ZnO when substituted with the magnetic transition metal ions Mn and Co, with substituent fraction ranging from x=0.02 to x=0.15. The magnetic properties were measured as a function of magnetic field and temperature and we find no evidence for magnetic ordering in these systems down to T=2 K. The magnetization can be fit by the sum of a Curie-Weiss term with a Weiss temperature of Theta>100 K and a Curie term. We attribute this behavior to contributions from both tM ions with tM nearest neighbors and from isolated spins. This particular functional form for the susceptibility is used to explain why no ordering is observed in tM substituted ZnO samples despite the large values of the Weiss temperature. We also discuss in detail the methods we used to minimize any impurity contributions to the magnetic signal.

引用

页数：5

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