Superconducting radio‐frequency (SRF) resonators are critical components for particle accelerator applications, such as free‐electron lasers, and for emerging technologies in quantum computing. Developing advanced materials and their deposition processes to produce RF superconductors that yield nΩ surface resistances is a key metric for the wider adoption of SRF technology. Here, ZrNb(CO) RF superconducting films with high critical temperatures (
Voltage‐tunable dielectric materials are widely used for microwave‐frequency signal processing. Among tunable dielectric thin films, (SrTiO3)
- Publication Date:
- NSF-PAR ID:
- 10063617
- Journal Name:
- Advanced Materials Technologies
- Volume:
- 3
- Issue:
- 8
- ISSN:
- 2365-709X
- Publisher:
- Wiley Blackwell (John Wiley & Sons)
- Sponsoring Org:
- National Science Foundation
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Abstract T c) achieved for the first time under ambient pressure are reported. The attainment of aT cnear the theoretical limit for this material without applied pressure is promising for its use in practical applications. A range ofT c, likely arising from Zr doping variation, may allow a tunable superconducting coherence length that lowers the sensitivity to material defects when an ultra‐low surface resistance is required. The ZrNb(CO) films are synthesized using a low‐temperature (100 – 200 °C) electrochemical recipe combined with thermal annealing. The phase transformation as a function of annealing temperature and time is optimized by the evaporated Zr‐Nb diffusion couples. Through phase control, one avoids hexagonal Zr phases that are equilibrium‐stable but degradeT c. X‐ray and electron diffraction combined with photoelectron spectroscopy reveal a system containing cubic β‐ZrNb mixed with rocksalt NbC and low‐dielectric‐loss ZrO2. Proof‐of‐concept RF performance of ZrNb(CO) on an SRF sample test systemmore » -
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Abstract We report on the tunable and enhanced dielectric properties of tungsten (W) incorporated gallium oxide (Ga2O3) polycrystalline electroceramics for energy and power electronic device applications. The W‐incorporated Ga2O3(Ga2−2xWxO3, 0.00 ≤ x ≤ 0.20; GWO) compounds were synthesized by the high‐temperature solid‐state chemical reaction method by varying the W‐content. The fundamental aspects of the dielectric properties in correlation with the crystal structure, phase, and microstructure of the GWO polycrystalline compounds has been investigated in detail. A detailed study performed ascertains the W‐induced changes in the dielectric constant, loss tangent (tan
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