基于二氧化钛的材料有望成为超导体的新绝缘体

For Immediate Release

贾斯汀·施瓦茨（Justin Schwartz）博士 justin_schwartz@ncsu.edu 919.515.0493

Dr. Sasha Ishmael saishmae@ncsu.edu 919.515.5063

Matt Shipman matt_shipman@ncsu.edu 919.515.6386

来自北卡罗来纳州立大学的研究显示s that a type of modified titania, or titanium dioxide, holds promise as an electrical insulator for superconducting magnets, allowing heat to dissipate while preserving the electrical paths along which current flows. Superconducting magnets are being investigated for use in next-generation power generating technologies and medical devices.

Regular conductors conduct electricity, but a small fraction of that energy is lost during transmission. Superconductors can handle much higher currents per square centimeter and lose virtually no energy through transmission. However, superconductors only have these desirable properties at low temperatures.

“Superconducting magnets need electrical insulators to ensure proper operation,” says Dr. Sasha Ishmael, a postdoctoral researcher at NC State and lead author of a paper describing the work. “Changing the current inside the superconductor is important for many applications, but this change generates heat internally. The magnets will operate much more safely if the electrical insulators are able to shed any excess heat. Otherwise, the higher temperatures could destroy the superconductor.

“This titania-based material is up to 20 times better at conducting heat than comparable electrical insulators,” Ishmael says. “It has characteristics that are very promising for use as electrical insulators for superconducting technologies.”

The precise chemical composition of the modified titania is proprietary information. The material’s development and characterization was a joint effort between NC State and nGimat LLC, based in Lexington, Kentucky.

“We’re now looking at the effect of radiation on this material, to determine if it can be used for high energy physics applications, such as particle colliders,” says Dr. Justin Schwartz, senior author of the paper and Kobe Steel Distinguished Professor and head of the Department of Materials Science and Engineering at NC State.

The paper, “Thermal conductivity and dielectric properties of a TiO₂-based electrical insulator for use with high temperature superconductor-based magnets,” is published online in the journalSuperconductor Science and Technology. The paper was co-authored by M. Slomski, H. Luo, J.F. Muth, T. Paskova, and W. Straka of NC State, and M. White, A. Hunt, N. Mandzy, and R. Nesbit of nGimat LLC.

The research was supported by the Department of Energy under grant DE-SC0004657-001 and the National Science Foundation under grant CBET-1336464.

-shipman-

Note to Editors:The study abstract follows.

“ TIO的热导率和介电性能₂-based electrical insulator for use with high temperature superconductor-based magnets”

Authors: S.A. Ishmael, M. Slomski, H. Luo, J.F. Muth, T. Paskova, W. Straka, and J. Schwartz, North Carolina State University; M. White, A. Hunt, N. Mandzy, and R. Nesbit, nGimat LLC.

Published：8月20日Superconductor Science and Technology

DOI: 10.1088/0953-2048/27/9/095018

Abstract:淬火保护是阻碍基于高温超导体（HTS）的磁铁应用的实施的剩余挑战。这主要是由于BI中观察到的缓慢正常区域传播速度（NZPV）₂Sr₂CaCu₂O_X(Bi2212) and (RE)Ba₂铜₃O_7-x（REBCO）系统。最近的计算和实验结果显示，转向转向NZPV的显着改善，导致磁铁更稳定，更易于通过三维正常区域的生长[1，2]进行保护。这些改进是通过替换传统的绝缘材料（例如Kapton和Mullite编织物）的薄，热导电的，电胰岛的陶瓷氧化物涂层来实现的。本文报告了依赖温度依赖的热性能，氧化钛的电击穿极限和微结构特性（TIO₂）绝缘和掺杂的tio₂- 基于专有的绝缘材料（掺杂型）₂）以前显示以增强淬灭行为[2]。报道了77 K处的击穿电压从〜1.5 kV到5 kV不等。在4.2 K时，Tio₂increases the thermal conductivity of polyimide by about a factor of 10. With the addition of a dopant, thermal conductivity is increased by an additional 13%, and a high temperature heat treatment increases it by nearly an additional 100%. Similar increases are observed at 77 K and room temperature. These results are understood in the context of the various microstructures observed.