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Mapping Delocalization of Impurity Bands across Archetypal Mott-Anderson Transition
M Parzer1, F Garmroudi2, A Riss1
1Technische Universität Wien, Institute of Solid State Physics, 1040 Vienna, Austria.
Physical Review Letters
|August 27, 2025
Summary
Researchers tuned charge transport in Fe-V-Al Heusler compounds by adjusting iron content. They observed a transition from localized to delocalized electronic states, achieving temperature-independent resistivity for electronic applications.
Area of Science:
- Condensed matter physics
- Materials science
- Solid-state chemistry
Background:
- Controlling charge transport in solids is vital for electronics.
- Impurities and disorder often hinder coherent conduction.
Purpose of the Study:
- To control electronic band formation from impurity states.
- To investigate charge carrier localization and delocalization in Fe-V-Al Heusler compounds.
Main Methods:
- Density-functional theory (DFT) calculations.
- Specific heat and electrical resistivity measurements.
- Thermoelectric measurements.
Main Results:
- Fe content reduction controls band buildup from impurity states.
- Anderson localization observed at low V concentrations (0
- Mott-Anderson transition observed with increasing V concentration, forming mobility edges.
- Delocalization in V3Al leads to temperature-independent resistivity up to 700 K, reaching the Mott-Ioffe-Regel limit.
Conclusions:
- Electronic band structure and charge transport can be tailored by compositional changes in Fe-V-Al compounds.
- The Mott-Anderson transition governs the shift from localized to delocalized states.
- Achieved temperature-independent resistivity offers potential for stable electronic device applications.
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