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Half-Metallicity in Heusler Alloys
Research Guide

What is Half-Metallicity in Heusler Alloys?

Half-metallicity in Heusler alloys refers to the electronic structure where one spin channel is metallic and the other is insulating at the Fermi level, yielding 100% spin polarization.

Density functional theory calculations predict half-metallic properties in compounds like Co2MnSi and Co2FeSi (Kandpal et al., 2007, 802 citations). Experimental verification includes direct observation via spin-resolved photoemission (Jourdan et al., 2014, 396 citations). Reviews cover band structure to many-body effects (Katsnelson et al., 2008, 991 citations).

Curated Papers

Key Challenges

Why It Matters

Half-metallicity enables efficient spin injection for spintronic devices like magnetic tunnel junctions. Kandpal et al. (2007) calculated properties of transition metal-based Heusler compounds showing high spin polarization. Wurmehl et al. (2005, 586 citations) applied Slater-Pauling rules to identify Co2FeSi with high Curie temperature. Jourdan et al. (2014) provided direct evidence in Co2MnSi, advancing spin valve applications. Park et al. (1998, 1373 citations) demonstrated half-metallicity experimentally, foundational for device efficiency.

Key Research Challenges

Maintaining gap under disorder

Atomic disorder reduces half-metallicity in full-Heusler alloys like Co2(Cr1-xFex)Al. Miura et al. (2004, 572 citations) used Korringa-Kohn-Rostoker method to show disorder destroys the minority spin gap. Robustness against defects remains critical for applications.

Bridging theory-experiment gap

DFT predictions often overestimate half-metallicity due to many-body effects. Katsnelson et al. (2008, 991 citations) reviewed discrepancies between band structure and experiments. Experimental confirmation like Park et al. (1998) is rare.

High Curie temperature stability

Many half-metallic Heuslers have low Curie temperatures limiting room-temperature use. Wurmehl et al. (2005) investigated Co2FeSi but stability under pressure needs improvement. Picozzi et al. (2002, 580 citations) studied Co2MnX under elevated pressure.

Essential Papers

Direct evidence for a half-metallic ferromagnet

J.-H. Park, E. Vescovo, H.-J. Kim et al. · 1998 · Nature · 1.4K citations

Half-metallic ferromagnets: From band structure to many-body effects

M. I. Katsnelson, V. Yu. Irkhin, L. Chioncel et al. · 2008 · Reviews of Modern Physics · 991 citations

A review of new developments in theoretical and experimental electronic structure investigations of half-metallic ferromagnets (HMF) is presented. Being semiconductors for one spin projection and m...

Calculated electronic and magnetic properties of the half-metallic, transition metal based Heusler compounds

Hem C Kandpal, Gerhard H Fecher, Claudia Felser · 2007 · Journal of Physics D Applied Physics · 802 citations

In this work, results of {\\it ab-initio} band structure calculations for\n$A_2BC$ Heusler compounds that have $A$ and $B$ sites occupied by transition\nmetals and $C$ by a main group element are p...

Origin and properties of the gap in the half-ferromagnetic Heusler alloys

I. Galanakis, P. H. Dederichs, N. Papanikolaou · 2002 · Physical review. B, Condensed matter · 709 citations

We study the origin of the gap and the role of chemical composition in the\nhalf-ferromagnetic Heusler alloys using the full-potential screened KKR method.\nIn the paramagnetic phase the C1_b compo...

Geometric, electronic, and magnetic structure of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mi>Co</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi>FeSi</mml:mi></mml:mrow></mml:math>: Curie temperature and magnetic moment measurements and calculations

S. Wurmehl, Gerhard H. Fecher, H.C. Kandpal et al. · 2005 · Physical Review B · 586 citations

In this work a simple concept was used for a systematic search for new\nmaterials with high spin polarization. It is based on two semi-empirical\nmodels. Firstly, the Slater-Pauling rule was used f...

<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Co</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mi mathvariant="normal">Mn</mml:mi><mml:mi>X</mml:mi></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mo>(</mml:mo><mml:mi>X</mml:mi><mml:mo>=</mml:mo><mml:mi mathvariant="normal">Si</mml:mi><mml:mo>,</mml:mo></mml:math>Ge, Sn) Heusler compounds: An<i>ab initio</i>study of their structural, electronic, and magnetic properties at zero and elevated pressure

Silvia Picozzi, A. Continenza, A. J. Freeman · 2002 · Physical review. B, Condensed matter · 580 citations

The structural, electronic, and magnetic properties of ${\mathrm{Co}}_{2}\mathrm{Mn}X$ $(X=\mathrm{Si},$ Ge, Sn) Heusler compounds have been determined by means of all-electron full-potential linea...

Atomic disorder effects on half-metallicity of the full-Heusler alloys<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Co</mml:mi></mml:mrow><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub></mml:mrow><mml:mo>(</mml:mo><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Cr</mml:mi></mml:mrow><mml:mrow><mml:mn>1</mml:mn><mml:mi>−</mml:mi><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mrow><mml:msub><mml:mrow><mml:mi mathvariant="normal">Fe</mml:mi></mml:mrow><mml:mrow><mml:mi>x</mml:mi></mml:mrow></mml:msub></mml:mrow><mml:mo>)</mml:mo><mml:mi mathvariant="normal">Al</mml:mi><mml:mo>:</mml:mo></mml:math>A first-principles study

Yoshio Miura, Kazutaka Nagao, Masafumi Shirai · 2004 · Physical Review B · 572 citations

We investigate the atomic disorder effects on the half-metallicity of the full-Heusler alloy ${\mathrm{Co}}_{2}({\mathrm{Cr}}_{1\ensuremath{-}x}{\mathrm{Fe}}_{x})\mathrm{Al}$ from first principles ...

Reading Guide

Foundational Papers

Start with Park et al. (1998) for experimental evidence, then Katsnelson et al. (2008) review for theory, and Kandpal et al. (2007) for Heusler calculations.

Recent Advances

Jourdan et al. (2014) for Co2MnSi observation; Ouardi et al. (2013) on spin gapless Mn2CoAl.

Core Methods

Ab-initio DFT: full-potential KKR (Galanakis 2002), FLAPW (Picozzi 2002); Slater-Pauling rules (Wurmehl 2005).

How PapersFlow Helps You Research Half-Metallicity in Heusler Alloys

Discover & Search

Research Agent uses searchPapers and citationGraph to map half-metallicity literature from Kandpal et al. (2007, 802 citations) to citing works like Jourdan et al. (2014). exaSearch finds experimental confirmations; findSimilarPapers identifies Co2MnSi analogs.

Analyze & Verify

Analysis Agent applies readPaperContent to extract band structures from Galanakis et al. (2002), then verifyResponse with CoVe checks spin polarization claims against DFT data. runPythonAnalysis plots DOS curves with matplotlib; GRADE scores theoretical predictions (e.g., 90% reliability for Kandpal et al.).

Synthesize & Write

Synthesis Agent detects gaps in disorder studies beyond Miura et al. (2004); Writing Agent uses latexEditText for band structure figures, latexSyncCitations for 10+ references, and latexCompile for arXiv-ready reviews. exportMermaid visualizes Slater-Pauling rule diagrams.

Use Cases

"Plot minority spin DOS for Co2FeSi from literature data"

Research Agent → searchPapers → Analysis Agent → runPythonAnalysis (NumPy/matplotlib recreates DOS from Wurmehl et al. 2005 data) → researcher gets publication-ready plot with statistical fit.

"Write review section on half-metallicity gaps with citations"

Synthesis Agent → gap detection → Writing Agent → latexEditText + latexSyncCitations (Galanakis 2002, Katsnelson 2008) + latexCompile → researcher gets compiled LaTeX PDF section.

"Find GitHub repos with Heusler DFT code for half-metals"

Research Agent → citationGraph on Kandpal 2007 → Code Discovery (paperExtractUrls → paperFindGithubRepo → githubRepoInspect) → researcher gets verified VASP/Wien2k scripts for Co2MnSi simulations.

Automated Workflows

Deep Research workflow scans 50+ papers from Park (1998) to Ouardi (2013), producing structured report with spin polarization tables. DeepScan applies 7-step verification to Jourdan (2014) photoemission data. Theorizer generates hypotheses on spin gapless extensions from Picozzi (2002).

Try Doxa for Half-Metallicity in Heusler Alloys Research

Frequently Asked Questions

What defines half-metallicity in Heusler alloys?

One spin channel metallic, other insulating at Fermi level, giving 100% polarization (Katsnelson et al., 2008).

What methods verify half-metallicity?

DFT with FLAPW or KKR (Galanakis et al., 2002; Kandpal et al., 2007); experiments via spin-resolved PES (Jourdan et al., 2014; Park et al., 1998).

What are key papers on Heusler half-metals?

Park et al. (1998, 1373 citations, first evidence); Kandpal et al. (2007, 802 citations, calculations); Wurmehl et al. (2005, 586 citations, Co2FeSi).