STRUCTURE, MAGNETIC PROPERTIES AND GIANT MAGNETORESISTANCE OF YMn6Sn6-xGax (x=0-0.6) COMPOUNDS

• 来源期刊: 中国物理(英文版)
• 学科: 物理学
• 关键词: structure magnetic properties magnetoresistance
• 年，卷（期）: 2001,（4）
• 页码范围: 345-348
• 页数: 4页
• 分类号: O4
• 语种: 英文

摘要

Structure, magnetic and transport properties of YMn6Sn6-xGax (0 ≤ x ≤ 0.6) compounds with a HfFe6Ge6-type structure were investigated. It was found that the Ga substitution leads to a contraction of the unit-cell volume. A transition from an antiferromagnetic to a ferromagnetic (or ferrimagnetic) state can be observed for samples (0.1 ≤ x ≤ 0.2) with increasing temperature. The antiferro-ferromagnetic transition for samples with x ≤ 0.2 can also be induced by an external field. The required field is very low, and decreases with increasing Ga concentration. More Ga concentration (x ≥ 0.3) leads to the samples being ferromagnetic in the whole temperature range below the Curie temperature. The Ga substitution weakens the interlayer magnetic coupling between the Mn spins. Corresponding to the metamagnetic transition, a magnetoresistance as large as 32% under a field of 5 T was observed at 5 K for the sample with x=0.2.