Microstructure, magnetic and transport properties of a Mn2CoAl Heusler compound
この論文をさがす
説明
Abstract We report a detailed analysis of microstructure, magnetic and transport properties of a stoichiometric Mn 2 CoAl Heusler alloy, which has been predicted to be a spin-gapless semiconductor (SGS). Microstructure analysis revealed that the main phase was Mn 1.8 Co 1.4 Al 0.8 rather than Mn 2 CoAl; this stable compound remained even for a Co-rich composition. Along with the Mn 1.8 Co 1.4 Al 0.8 phase, a disk-shaped Mn-rich precipitate phase was observed in both annealed stoichiometric and Co-rich Mn 2 CoAl alloys. Atomically resolved energy-dispersive X-ray spectroscopy mappings revealed that the Mn 1.8 Co 1.4 Al 0.8 phase has a disordered inverse XA Heusler structure with Mn (A) and Al (C) sites partially substituted by Co and Mn, respectively. First-principles calculations based on the observed disordered structure suggest that the Heusler phase is not SGS but half-metallic. However, both annealed stoichiometric and Co-rich Mn 2 CoAl exhibit semiconducting-like resistivity and low anomalous Hall conductivity. These transport properties were regarded as the signatures of SGS in the previous studies; however, it could be due to localization of charged carriers due to the intersection of the Fermi level with Mn 3 d and Co 3 d states in Mn 1.8 Co 1.4 Al 0.8 . This study demonstrates that not only measurements of transport properties but also careful microstructure inspections are essential to validate SGS properties in the theoretically predicted SGS candidates among Heusler compounds.
収録刊行物
-
- Acta Materialia
-
Acta Materialia 176 33-42, 2019-09
Elsevier BV
- Tweet
詳細情報 詳細情報について
-
- CRID
- 1360005516594052864
-
- ISSN
- 13596454
-
- 資料種別
- journal article
-
- データソース種別
-
- Crossref
- KAKEN
- OpenAIRE