Structural and Magnetic Properties of Dilute Magnetic Oxide Based on Nanostructured Co-Doped Anatase TiO2 (Ti1-xCoxO2-δ)

被引：21

作者：

de Souza, Talita E. ^{[1
]}

Mesquita, Alexandre ^{[1
]}

de Zevallos, Angela O. ^{[1
]}

Beron, Fanny ^{[2
]}

Pirota, Kleber R. ^{[2
]}

Neves, Person P. ^{[1
]}

Doriguetto, Antonio C. ^{[1
]}

de Carvalho, Hugo B. ^{[1
]}

机构：

[1] Univ Fed Alfenas, BR-37130000 Alfenas, MG, Brazil

[2] Univ Estadual Campinas, Inst Fis Gleb Wataghin, BR-13083859 Campinas, SP, Brazil

来源：

JOURNAL OF PHYSICAL CHEMISTRY C | 2013年 / 117卷 / 25期

基金：

巴西圣保罗研究基金会;

关键词：

ROOM-TEMPERATURE; OXYGEN VACANCY; FERROMAGNETISM; SUSCEPTIBILITY;

D O I：

10.1021/jp4017129

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Nanostructured Co-doped anatase TiO2 (Ti1-xCoxO2-delta) samples were prepared and studied with particular emphasis on their compositional, structural, and magnetic properties. A detailed microstructural analysis was carried out to investigate the nature of the Co incorporation into the anatase TiO2 matrix. By combining different techniques, we confirmed the replacement of Ti4+ by Co2+ ions in the anatase TiO2 structure. Neither segregated secondary phases nor Co-rich nanocrystals were detected. Co doping was found to introduce oxygen vacancies into the system by means of a charge-compensation process. Superconducting quantum interference device magnetometry demonstrated paramagnetic Curie-Weiss behavior with antiferromagnetic interactions even in the presence of a high density of oxygen vacancies. The fitting of the M(H) curves in the limits of low and high temperatures enable the fractions of isolated and antiferromagnetically coupled Co ions to be extracted. We discuss the observed magnetic behavior of our samples considering the current main theories for the magnetic properties of dilute magnetic oxides.

引用

页码：13252 / 13260

页数：9

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