Claude agents propose room-temperature magnetic semiconductors
Awaiting review
The takeaway
Vals AI reports two candidate magnets for spintronic memory found by a team of Claude Opus 5.5 agents running DFT (PBE+U and HSE06). The first is a new design, YBaMnFeO₅, predicted to order up to about 420–490 K. The second is a Prussian-blue cyanide made in 1999 that nobody had identified as this kind of magnet. Nothing has been measured yet, and the new compound may be hard to make in its ordered form.
Status
- Claim
Awaiting review
- Our reporting
- Medium confidence
- Verification
- Unverified claim
- Importance
- 2 of 5
- Last verified
- 26 October 2026
Your AI and this story
- GPT-6 Astra157 days after its cutoff
- Claude Opus 5.596 days after its cutoff
- Gemini 4 Hydrogen187 days after its cutoff
- Grok 4.7126 days after its cutoff
None of these four assistants can know about it. The closest, Claude Opus 5.5, stops 96 days before it.
Key facts
- Method: Claude Opus 5.5 agents ran density functional theory at two levels, PBE+U (fast) and HSE06 (more accurate); the post does not describe the agent setup further
- YBaMnFeO₅: predicted band gap 2.35 eV; spin windows 1.0 eV (holes) and 1.4 eV (electrons); ordering to ~420 K (raw) / ~490 K (calibrated)
- KV[Cr(CN)₆] (1999): predicted gap ~2.1 eV; spin windows 2.6 eV (holes) and 1.6 eV (electrons); the 1999 sample ordered to 376 K with a small residual moment (0.125 μB per formula unit)
- Caveats (post): predictions assume a perfect dry crystal. YBaMnFeO₅ needs an ordered Mn/Fe checkerboard that simulations show disordering near 950 K, below typical synthesis temperatures of 900–1300 °C (‘A scrambled crystal loses the spin sorting, so this design may be hard to make in its useful form’). The 1999 material is a water-containing powder, and the two DFT levels disagree on whether its hole window survives
- Found late, through Import AI 478 (26 Oct).. Note: the 1999 compound is the cyanide; the five-element oxide is the new design
What happened
Vals AI, known for model evaluations, published a materials-science result. A team of Claude Opus 5.5 agents searched for “Luttinger-compensated” magnets. These materials have zero net magnetism but spin-split electron bands, a combination wanted for fast, dense memory. The agents ran DFT calculations at two levels of accuracy. One candidate is a new layered oxide. The other is a cyanide that chemists made in 1999 without recognising this property.
Why it matters
It is a small but typical example of agent-driven materials screening: plausible candidates and a rediscovered old compound, with every number still a simulation. The authors’ own caveats (disorder at synthesis temperatures, water in the old sample) show how far a prediction is from a usable material.
What is disputed or not yet verified
| Verification | Unverified computational prediction (blog post, no paper, no experiment) |
|---|
Sources
2 sources from 2 sites. Numbers match the chips in the text.
2 sources: 1 primary, 1 press
Primary
Press
- Import AI 478 (Jack Clark, 26 Oct 2026)importai.substack.com, press
Changes
- Filed. Found late through Import AI 478