共查询到20条相似文献,搜索用时 46 毫秒
1.
2.
4.
光催化技术被认为是最有前景的环境污染处理技术,这就使得光催化剂材料备受瞩目.近年来,铁电材料作为新型光催化剂材料受到人们越来越多的关注,其原因在于铁电材料特有的自发极化有望解决催化反应过程中的电子-空穴对复合问题,进而提高光催化活性.本文从两个方面对铁电极化如何影响光催化进行综述:一方面,从铁电极化入手归纳总结其对电子-空穴对分离的影响,进而更深入地从极化引发的退极化场和能带弯曲两个部分来阐述具体的影响机理;另一方面,为了消除静电屏蔽,分别从温度、应力(应变)、电场三个外场因素调控极化入手,归纳总结外场调控极化对电子-空穴对分离的影响,进而影响光催化活性.最后对该领域今后的发展前景进行了展望. 相似文献
5.
新型铁电存贮器和铁电薄膜的脉冲激光沉积 总被引:2,自引:0,他引:2
结合自己的工作,介绍了目前国际上新型功能材料与器件研究的热点之一-铁电集成和铁电存贮器的研究开发;报道了用脉冲激光沉积这种新型成膜技术制备铁电PZT薄膜的些实验结果。 相似文献
6.
集成铁电学与铁电集成薄膜 总被引:12,自引:0,他引:12
介绍了集成铁电学的基本概念,评述了当前集成铁电材料与器件研究中的主要问题,概略叙述了作者提出的铁电集成薄膜及其在多功能器件和灵巧器件上的应用。 相似文献
8.
主要讨论了铁电薄膜用于研制铁电存贮器的进展情况,探讨了目前围绕电级,空间电荷,畴钉扎,应力和微结构等几个方面对铁电薄膜贮存器疲劳特性的影响,论述了铁电薄膜存贮器的研究现状和存在的一些问题。 相似文献
9.
10.
电子学及超导体等领域的发展,推动了铁电研究的进一步深入和发展。同步辐射的多种优异的特性使之在凝聚态物理中得到了广泛应用,也为铁电研究提供了强有务的研究手段。本语文结合几处具体实验手段,简要介绍同步辐射在铁电研究中的一些应用,包括X射线吸收、X射线驻波、X射线散射、光学光谱、光电子能谱及形貌术,对光声光热也作子简单介绍。 相似文献
11.
In 1992, E.E. Podkletnov and R. Nieminen found
that under certain conditions, ceramic superconductor with
composite structure reveals weak shielding properties against
gravitational force. In classical Newton's theory of gravity and
even in Einstein's general theory of gravity, there are no grounds
of gravitational shielding effects. But in quantum gauge theory of
gravity, the gravitational shielding effects can be explained in a
simple and natural way. In quantum gauge theory of gravity,
gravitational gauge interactions of complex scalar field can be
formulated based on gauge principle. After spontaneous symmetry
breaking, if the vacuum of the complex scalar field is not stable
and uniform, there will be a mass term of gravitational gauge
field. When gravitational gauge field propagates in this unstable
vacuum of the complex scalar field, it will decays exponentially,
which is the nature of gravitational shielding effects. The
mechanism of gravitational shielding effects is studied in this
paper, and some main properties of gravitational shielding effects
are discussed. 相似文献
12.
Kornev IA Bellaiche L Bouvier P Janolin PE Dkhil B Kreisel J 《Physical review letters》2005,95(19):196804
Ab initio simulations and experimental techniques are combined to reveal that, unlike what was commonly accepted for more than 30 years, perovskites and related materials enhance their ferroelectricity as hydrostatic pressure increases above a critical value. This unexpected high-pressure ferroelectricity is different in nature from conventional ferroelectricity because it is driven by an original electronic effect rather by long-range interactions. 相似文献
13.
14.
J. Fousek 《Czechoslovak Journal of Physics》1966,16(11):909-910
15.
Mostovoy M 《Physical review letters》2006,96(6):067601
It was recently observed that the ferroelectrics showing the strongest sensitivity to an applied magnetic field are spiral magnets. We present a phenomenological theory of inhomogeneous ferroelectric magnets, which describes their thermodynamics and magnetic field behavior, e.g., dielectric susceptibility anomalies at magnetic transitions and sudden flops of electric polarization in an applied magnetic field. We show that electric polarization can also be induced at domain walls and that magnetic vortices carry electric charge. 相似文献
16.
17.
Yibo Wang Siqi Jiang Jingkuan Xiao Xiaofan Cai Di Zhang Ping Wang Guodong Ma Yaqing Han Jiabei Huang Kenji Watanabe Takashi Taniguchi Yanfeng Guo Lei Wang Alexander S. Mayorov Geliang Yu 《Frontiers of Physics》2022,17(4):43504
Van der Waals (vdW) assembly of two-dimensional materials has long been recognized as a powerful tool for creating unique systems with properties that cannot be found in natural compounds [Nature 499, 419 (2013)]. However, among the variety of vdW heterostructures and their various properties, only a few have revealed metallic and ferroelectric behaviour signatures [Sci. Adv. 5, eaax5080 (2019); Nature560, 336 (2018)]. Here we show ferroelectric semimetal made of double-gated double-layer graphene separated by an atomically thin crystal of hexagonal boron nitride. The structure demonstrates high room temperature mobility of the order of 10 m2·V−1·s−1 and exhibits ambipolar switching in response to the external electric field. The observed hysteresis is reversible and persists above room temperature. Our fabrication method expands the family of ferroelectric vdW compounds and offers a promising route for developing novel phase-changing devices. A possible microscopic model of ferroelectricity is discussed. 相似文献
18.
We report discovery of collinear-magnetism-driven ferroelectricity in the Ising chain magnet Ca3Co2-xMn(x)O6 (x approximately 0.96). Neutron diffraction shows that Co2+ and Mn4+ ions alternating along the chains exhibit an up-up-down-down ( upward arrow upward arrow downward arrow downward arrow) magnetic order. The ferroelectricity results from the inversion symmetry breaking in the upward arrow upward arrow downward arrow downward arrow spin chain with an alternating charge order. Unlike in spiral magnetoelectrics where antisymmetric exchange coupling is active, the symmetry breaking in Ca3(Co,Mn)2O6 occurs through exchange striction associated with symmetric superexchange. 相似文献
19.
20.
It is shown that by adding potassium nitrate (1 % by weight) to compensated cholesteric mixtures (cholesteryl chloride-cholesteryl myristate 63.63:36.37% by weight and cholesteryl laurate-cholesteryl chloride 35.65% by weight) or to smectic sitosteryl undecilenate, the mixtures exhibit ferroelectric behaviour. Values of Ps = 10-9 - 10-8 C/cm2 were obtained in the high-temperature range. In compensated cholesteric mixtures, the spontaneous polarisation reached a minimum at a temperature corresponding to the cholesteric-nematic transition. The results are explained by assuming coupling between the dipoles of the antiferroelectric KNO3 and the dipoles of the mesogenic compound. 相似文献