Related Experiment Video
Updated: May 20, 2026
08:55
Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
Ferroelectric order in individual nanometre-scale crystals
Mark J Polking1, Myung-Geun Han, Amin Yourdkhani
1Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, USA.
Nature Materials
|July 10, 2012
Summary
Ferroelectric order persists in single-domain nanocrystals down to 5nm. Particle morphology and boundary conditions control ferroelectric distortions, enabling potential multi-Tbit/in² memory devices.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Ferroelectricity in finite-dimensional systems is of significant interest due to potential vortex polarization states and applications in nanomaterials.
- Understanding the nanoscale polarization structure and scaling limits of ferroelectric order is crucial for these applications.
Purpose of the Study:
- To determine the nanoscale polarization structure and scaling limit of ferroelectric order in individual nanocrystals.
- To investigate the role of particle morphology and electrostatic boundary conditions in ferroelectric coherence.
Main Methods:
- Aberration-corrected transmission electron microscopy (TEM) to map ferroelectric structural distortions.
- Holographic polarization imaging to visualize polarization states.
- Characterization of individual nanocrystals comprising a single ferroelectric domain.
Main Results:
- Ferroelectric structural distortions were mapped, revealing a linearly ordered and monodomain polarization state at nanometre dimensions.
- Room-temperature polarization switching was demonstrated in ferroelectric nanocrystals as small as approximately 5 nanometres.
- Ferroelectric coherence was found to be facilitated by controlled particle morphology and electrostatic boundary conditions.
Conclusions:
- Ferroelectric order persists down to ultimate nanoscale limits, with implications for next-generation memory devices.
- Particle morphology and boundary conditions are key factors in controlling ferroelectric distortions and coherence.
- This research paves the way for ultra-high-density memory technologies (multi-Tbit/in²).
Related Concept Videos
02:22Structures of Solids
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...
01:26Imperfections in Crystal Structure: Stoichiometric Point Defects
Schottky defects arise when some lattice points in a crystal, such as those in NaCl, remain unoccupied, creating lattice vacancies without disturbing the overall electrical neutrality of the crystal. This defect is common in ionic crystals where the positive and negative ions are similar in size, as seen in sodium chloride and cesium chloride. The presence of Schottky defects enables the crystal to conduct electricity to a small extent through an ionic mechanism. Electric fields cause nearby...
02:42Ionic Crystal Structures
Ionic crystals consist of two or more different kinds of ions that usually have different sizes. The packing of these ions into a crystal structure is more complex than the packing of metal atoms that are the same size.
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
01:29Determination of Crystal Structures
In the late 1800s, the revelation that light extended beyond visible wavelengths led to the discovery of X-rays by Wilhelm Roentgen. Recognized as high-energy electromagnetic radiation with short wavelengths, X-rays prompted exploration into their interaction with crystals. Max von Laue proposed in 1912 that the periodic arrangement of atoms, ions, or molecules in crystals would cause them to diffract X-rays, a hypothesis confirmed through experiments with copper sulfate and zinc sulfide...
01:18Unit Cells
A crystal's internal structure is an orderly array of atoms, ions, or molecules, and the details of this array significantly influence the solid's properties. In a crystal, periodically repeating 'structural motifs' - which could be atoms, molecules, or groups thereof - create a 'space lattice.' This is essentially a three-dimensional, infinite array of points, each surrounded by its neighbors in an identical way, forming the basic structure of the crystal.A 'unit cell' is a theoretical...
01:25Imperfections in Crystal Structure: Point, Line and Plane Defects
A perfect crystal, in theory, has a uniform structure with the same unit cell and lattice points throughout. However, any deviation from this periodic arrangement is known as an imperfection or defect. These defects can be categorized into three types: point, line, and plane defects.Point defects occur when there is a deviation from the ideal due to missing atoms, displaced atoms, or additional atoms. These imperfections might occur due to imperfect packing during crystallization or because of...