Novel tailor-made nanoferroelectric from building blocks

Dec 20, 2010 By Mikiko Tanifuji
Fig. An artificial superlattice assembled from perovskite nanosheets (A=Ca2Nb3O10, B=LaNb2O7). The success of growth of such well-controlled superlattices with a good interface quality enabled us to explore new properties of perovskite superlattices. By artificial structuring, the group found that the (LaNb2O7/Ca2Nb3O10) superlattice possesses a new form of interface coupling, which gives rise to ferroelectricity even at several nanometer thicknesses.

A research group at the Japan's National Institute for Materials Science have successfully developed a novel nanoferroelectric by a solution-based bottom-up nanotechnology.

A research group headed by MANA Scientist Dr. Minoru Osada and Principal Investigator Dr. Takayoshi Sasaki of the International Center for Materials Nanoarchitectonics at the National Institute for successfully developed a novel nanoferroelectric by a solution-based bottom-up nanotechnology.

Ferroelectric materials are one of dielectrics that possess spontaneous and reversible electric dipole moments — an electric polarization remains after applying and removing an external electric field, from which can be worked as a nonvolatile memory, representing "0" in one orientation and "1" in the other. Ferroelectric memory (FeRAM) features high-speed access, high endurance in write mode, low power consumption, non-volatility, and excellent tamper resistance. It is therefore ideal memory for use in smart cards, as well as cellular phones and other devices. The continuous downscaling of microelectronic circuits combined with increasing interest in ferroelectric thin films for FeRAMs is drawing great attention to ferroelectric nanostructures / nanofilms. Until recently, it was technologically difficult to stabilize ferroelectricity on the nanoscale.

Seeking to develop a new nanoferroelectrics, this research group created a superlattice film based molecularly-thin oxide nanosheets as building blocks. The group synthesized two different perovskite nanosheets (Ca2Nb3O10, LaNb2O7), and fabricated an artificial superlattice by alternately stacking of two nanosheets via solution-based layer-by-layer assembly, in the same way that children play with building blocks. By artificial structuring, the group found that, in contrast to the paraelectric nature of Ca2Nb3O10 and LaNb2O7, the (LaNb2O7/Ca2Nb3O10) superlattice possesses a new form of interface coupling, which gives rise to ferroelectricity at room temperature. This artificial superlattice exhibited robust ferroelectric properties even at several nanometer thicknesses, which is the world’s thinnest level. This achievement has a great potential for the rational design and construction of nanoferroelectrics, and will also open a new route to the development of lead-free ferroelectric devices desirable for future electronic equipments.

The results was published in ACS Nano on November 23.

Explore further: Nanotube cathode beats large, pricey laser

More information: pubs.acs.org/doi/abs/10.1021/n… s?journalCode=ancac3

Provided by National Institute for Materials Science

5 /5 (2 votes)
add to favorites email to friend print save as pdf

Related Stories

Reverse Chemical Switching of a Ferroelectric Film

Feb 25, 2009

(PhysOrg.com) -- Ferroelectric materials display a spontaneous electric polarization below the Curie temperature that can be reoriented, typically by applying an electric field. In this study, researchers ...

Tunneling Across a Ferroelectric

Jul 14, 2006

University of Nebraska-Lincoln physicist Evgeny Tsymbal's groundbreaking identification of an emerging research field in electronic devices earned publication this week in Science magazine.

Recommended for you

Nanotube cathode beats large, pricey laser

6 hours ago

Scientists are a step closer to building an intense electron beam source without a laser. Using the High-Brightness Electron Source Lab at DOE's Fermi National Accelerator Laboratory, a team led by scientist ...

Solar cell compound probed under pressure

Sep 25, 2014

Gallium arsenide, GaAs, a semiconductor composed of gallium and arsenic is well known to have physical properties that promise practical applications. In the form of nanowires and nanoparticles, it has particular ...

User comments : 0