Department of Condensed Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.
Phys Rev Lett. 2010 May 7;104(18):187601. doi: 10.1103/PhysRevLett.104.187601.
The dielectric response of PbTiO(3)/SrTiO(3) superlattices is studied using electrical and structural measurements. While the dielectric response of paraelectric superlattices is well accounted for by the lattice contribution, superlattices with ferroelectric compositions exhibit an enhanced permittivity. X-ray diffraction allowed the presence of ordered nanodomains in ferroelectric superlattices to be established and their displacement under an applied bias to be directly probed, demonstrating that the enhanced permittivity in these artificial materials is due to domain wall motion.
采用电学和结构测量研究了 PbTiO(3)/SrTiO(3)超晶格的介电响应。虽然顺电超晶格的介电响应可以很好地用晶格贡献来解释,但具有铁电成分的超晶格表现出增强的介电常数。X 射线衍射允许确定铁电超晶格中有序纳米畴的存在,并直接探测在施加偏压下它们的位移,证明这些人工材料中增强的介电常数是由于畴壁运动所致。