氧化物多层电容器在广泛的温度范围内具有很大的电热效应
B Nair1, T Usui2, S Crossley1
1Department of Materials Science, University of Cambridge, Cambridge, UK.
Nature
|October 10, 2019
概括
新的电热材料为先进的热提供了显著的温度变化. 高品质的多层电容实现了接近室温的5.5K温度转移,改进了现有的磁热和电热技术.
科学领域:
- 固态物理
- 材料科学
- 热力学
背景情况:
- 热利用磁热和电热效应进行冷却,由磁场和电场驱动.
- 目前的原型受到工作体的小温度变化 (<3K) 的限制,阻碍了实际性能.
- 现有的技术依赖于永久磁铁或高电压, 造成成本和批量挑战.
研究的目的:
- 展示一种用于提高热性能的新型电热材料.
- 研究PbSc0.5Ta0.5O3多层电容中的电热效应.
- 通过先进的电热材料探索热设计的潜力.
主要方法:
- 使用PbSc0.5Ta0.5O3制造高质量的多层电容器.
- 应用超临界电场 (29.0 V/μm) 在基里温度 (290 K) 以上以驱动铁电相变.
- 使用兰道理论验证相位过渡行为.
- 在电容器的中心区域测量温度变化.
主要成果:
- 在广泛的温度范围内,PbSc0.5Ta0.5O3电容具有很大的电热效应.
- 在室温附近的峰值温度变化达到5.5K.
- 在176K范围内观察到超过3K的温度变化.
- 一级铁电相变的超临界驱动得到确认.
结论:
- 高质量的PbSc0.5Ta0.5O3多层电容显示出显著的电热效应.
- 这些材料为目前的磁热和电热工作体提供了有希望的替代品.
- 使用这些电容器重新利用现有的磁热热设计,可以在没有重磁铁的情况下提高性能.
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