Nanostructured Ferroelectrics: Fabrication and Structure–Property Relations

Abstract

With the continued demand for ultrahigh density ferroelectric data storage applications, it is becoming increasingly important to scale the dimension of ferroelectrics down to the nanometer-scale region and to thoroughly understand the effects of miniaturization on the materials properties. Upon reduction of the physical dimension of the material, the change in physical properties associated with size reduction becomes extremely difficult to characterize and to understand because of a complicated interplay between structures, surface properties, strain effects from substrates, domain nucleation, and wall motions. In this Review, the recent progress in fabrication and structure-property relations of nanostructured ferroelectric oxides is summarized. Various fabrication approaches are reviewed, with special emphasis on a newly developed stencil-based method for fabricating ferroelectric nanocapacitors, and advantages and limitations of the processes are discussed. Stress-induced evolutions of domain structures upon reduction of the dimension of the material and their implications on the electrical properties are discussed in detail. Distinct domain nucleation, growth, and propagation behaviors in nanometer-scale ferroelectric capacitors are discussed and compared to those of micrometer-scale counterparts. The structural effect of ferroelectric nanocapacitors on the domain switching behavior and cross-talk between neighboring capacitors under external electric field is reviewed.

The Atomistic Structure of Metal/Ceramic Interfaces Is the Key Issue for Developing Better Properties

“…The smaller they become, the harder it is to extinguish them, which means they are self-stabilized. This splitting in physical properties below a critical radius can be used for engineering purposes, as indicated by calculations of the author [61,62] and confirmed experimentally by others [63]. One popular example for functional nano-materials are isolated Fe-particles with their ability of fast spin response to applied magnetic fields.…”

Intrinsic anomalous ferroelectricity in vertically aligned LiNbO3-type ZnSnO3 hybrid nanoparticle-nanowire arrays

“…12 In nanostructures, complicated interplay among structures, surface charges, strain effects, and domain wall motion changes the long-and short-range ordering of dipoles inside the FE material. 11,[22][23][24][25][26] Consequently, nanostructured FE films exhibit uniquely different properties from their bulk counterparts, or homogeneous thin films. 11,[22][23][24][25][26] The measurement of the intrinsic FE properties in nanostructured materials is also a challenge.…”

Following Strain-Induced Mosaicity Changes of Ferroelectric Thin Films by Ultrafast Reciprocal Space Mapping

“…[1] Epitaxial strain engineering and the careful choice of mechanical and electrical boundary conditions enable a direct influence on these functionalities. [2][3][4][5][6] Structural defects and nanoscale inhomogeneities, such as dislocations and domains, typically affect the properties of functional oxides and have been extensively studied by experiment and theory. [7,8] Ultrafast x-ray diffraction (UXRD) emerged as a powerful tool to observe lattice motion in real time [9][10][11] and has provided a deeper insight in the structure-property relations of functional oxides on ultrashort timescales.…”