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Rational design of new materials for spintronics: Co2FeZ (Z=Al, Ga, Si, Ge)
Benjamin Balke1, Sabine Wurmehl1, Gerhard H Fecher1
1Institut für Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universität Mainz, D-55099 Mainz, Germany.
Science and Technology of Advanced Materials
|November 24, 2016
Summary
New Heusler compounds show promise for spintronic applications, offering high Curie temperatures and enabling room-temperature operation in devices like tunnel magnetoresistance junctions.
Area of Science:
- Materials Science
- Solid State Physics
- Condensed Matter Physics
Background:
- Spintronics requires novel materials, particularly stable half-metallic ferromagnets and ferromagnetic semiconductors with high Curie temperatures.
- Heusler compounds are emerging as promising candidates for spintronic applications due to their tunable magnetic and electronic properties.
Approach:
- Investigated magnetic Heusler compounds, focusing on Co2-based materials for spintronic applications.
- Utilized computational simulations and experimental techniques like X-ray Diffraction (XRD) and Extended X-ray Absorption Fine Structure (EXAFS) to understand structure-property relationships.
Key Points:
- Co2FeSi exhibits a high Curie temperature of 1120 K.
- A tunnel magnetoresistance (TMR) device using Co2FeAl0.5Si0.5 demonstrated over 200% TMR effect at room temperature.
- The Co2FeAl1-xSix series shows half-metallic ferromagnetism, with electron doping stabilizing the minority spin gap.
Conclusions:
- Heusler compounds, particularly Co2-based ones, offer significant potential for advanced spintronic devices.
- Understanding and controlling crystal structure (e.g., L21 vs. B2) is crucial for achieving desired half-metallic properties.
- Co2FeGa and Co2FeGe are identified as suitable new materials for magnetic tunnel junctions based on their L21 structure and high predicted Curie temperatures.
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