Characterization of CoCrFeO4 Nanocrystals Prepared by a Sol-Gel Method

• 来源期刊: 中国物理快报(英文版)
• 学科: 物理学
• 年，卷（期）: 2001,（5）
• 所属期刊栏目: CROSS-DISCIPLINARY PHYSICS
• 页码范围: 692-694
• 页数: 3页
• 分类号: O4
• 语种: 英文

摘要

CoCrFeO4 nanocrystals have been synthesized using a sol-gel method. The specimen has an average grain size of 8.1 nm. The zero-field-cooled and field-cooled curves show a superparamagnetic transition occurring at a blocking temperature of TB ≈ 249 K. The increase in coercivity of CoCrFeO4 nanocrystals with the decreasing temperature has been detected below the blocking temperature and could be explained by the Stoner-Wohlfarth theory. The temperature dependence of saturation magnetization shows that Bloch's law holds but with the Bloch exponent lower than the bulk value.