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Abstract While induced spin polarization of a palladium (Pd) overlayer on antiferromagnetic and magneto-electric Cr2O3(0001) is possible because of the boundary polarization at the Cr2O3(0001), in the single domain state, the Pd thin film appears to be ferromagnetic on its own, likely as a result of strain. In the conduction band, we find the experimental evidence of ferromagnetic spin polarized in Pd thin films on a Cr2O3(0001) single crystal, especially in the thin limit, Pd thickness of around 1–4 nm. Indeed there is significant spin polarization in 10 Å thick Pd films on Cr2O3(0001) at 310 K, i.e. above the Néel temperature of bulk Cr2O3. While Cr2O3(0001) has surface moments that tend to align along the surface normal, for Pd on Cr2O3, the spin polarization contains an in-plane component. Strain in the Pd adlayer on Cr2O3(0001) appears correlated to the spin polarization measured in spin polarized inverse photoemission spectroscopy. Further evidence for magnetization of Pd on Cr2O3is provided by measurement of the exchange bias fields in Cr2O3/Pd(buffer)/[Co/Pd]nexchange bias systems. The magnitude of the exchange bias field is, over a wide temperature range, virtually unaffected by the Pd thickness variation between 1 and 2 nm.
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This content will become publicly available on March 1, 2027
Cr 2 AlC: A High‐Temperature Transparent Conducting Ceramic
ABSTRACT Transparent conductors with high conductivity, optical transparency, and thermal stability are critical for next‐generation optoelectronic devices, yet such materials are scarce. Here, we demonstrate that epitaxial Cr2AlC(0001)/Al2O3(0001) layers exhibit a unique combination of these properties. The optical transmittance of ultrathin layers reaches 85% at 900 nm and remains above 21% across the near‐infrared (NIR)ultraviolet (UV) range, in good agreement with first‐principles optical properties predictions which reveal a small plasma frequency and a low cross‐section for interband transitions. Cr2AlC has a room‐temperature bulk resistivityρo= 42.5 µΩcm and an exceptionally small resistivity scaling with a negligible (<4%) resistivity increase down to 10 nm, an effective bulk electron mean free pathλ< 2 nm at both 295 and 77 K, and a temperature‐independent effectiveρoλ< 3 × 10−16Ωm2that is smaller than that of all known elemental metals. An 11.1‐nm‐thick Cr2AlC layer achieves a benchmarkΦTC≈ 0.004 Ω−1in the near infrared (900 nm), comparable to state‐of‐art transparent conductors including ultra‐thin silver and carbon‐based materials. These results, in combination with the known oxidation stability to 1073–1373 K, establish Cr2AlC as a uniquely robust, high‐temperature stable and scalable transparent conductor, paving the way for advanced extreme‐environment optoelectronics and photonics.
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- Award ID(s):
- 2328906
- PAR ID:
- 10698653
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- Advanced Materials Interfaces
- Volume:
- 13
- Issue:
- 6
- ISSN:
- 2196-7350
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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