Exploring of new semimetallic half-metals for three terminal devices

2014 Fiscal Year Final Research Report

• Project/Area Number: 25600070
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Applied materials
• Research Institution: Tohoku University
• Principal Investigator: MIZUKAMI Shigemi 東北大学, 原子分子材料科学高等研究機構, 教授 (00339269)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: ハーフメタル / 磁気抵抗素子 / 半金属 / ホイスラー合金 / エピタキシャル

Outline of Final Research Achievements

Mn-Co-Ga alloys have been studied for exploring of new materials having both half-metallic and semi-metallic properties. Single phase Mn-Co-Ga epitaxial films with cubic structure have been successfully grown on MgO single crystalline substrate. The films showed large electrical resistivity and metallic temperature dependence of resistivity. The Hall coefficient for the films changed the sign depending on Co concentration while their absolute values were not large, as expected in semimetal. On the other hand, magnetic tunnel junctions with Mn-Co-Ga electrode showed the enhanced magnetoresistance at low temperature and the junction resistance larger by a factor of ten than that of the junction with Co non-doped Mn-Ga. These results indicated that Mn-Co-Ga had unique electronic states.

Free Research Field

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