Hopping and Non-universal Conductivity in Half-Metallic CrO2 Composites

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2003,（5）
• 页码范围: 721-724
• 页数: 4页
• 语种: 英文

摘要

We study the dependence of resistivity p on conducting volume fraction p in CrO2/TiO2 magnetic composite that is composed of acicular half-metallic particles and spherical insulating particles. The measured percolation threshold was determined to be pc = 0.192. It is found that the conductivity exhibits a non-universal critical exponent t = 2.52 ± 0.08, which may be dominantly attributed to microstructure and higher-order hopping in this composite.