University of Pennsylvania engineers discover natural 'workbench' for nanoscale construction

Engineers at the University of Pennsylvania have taken a step toward simplifying the creation of nanostructures by identifying the first inorganic material to phase separate with near-perfect order at the nanometer scale. The finding provides an atomically tuneable nanocomposite “workbench” that is cheap and easy to produce and provides a super-lattice foundation potentially suitable for building nanostructures.

The findings appear in the August issue of Nature Materials.

Alerted by an unusual diffraction effect of a common ceramic material, researchers used imaging to identify a two-phase structural pattern ideal as the first step towards nanodevice construction. Practical application of nanotechnology will rely upon engineering’s ability to manipulate atoms and molecules into long-range order to produce materials with desired functionalities. The Penn findings provide a simpler method for the ordering of composite parts on the nanometer scale, which is integral to the incorporation of nano-objects such as particles and wires that make up nanodevices.

The material used in the Penn study is an ionically- conductive, crystalline ceramic (Nd_2/3-xLi_3x)TiO₃ that engineers observed with transmission electron microscopy. The powdered perovskite exhibited two distinct patterns at the atomic scale with identical periodicity: a nanoscale chessboard pattern and a diamond pattern that indicated periodic separation into two phases within the structure. This spontaneous separation of phases could present a new foundation on which to build nanodevice technology. This material – made using standard and easily reproducible ceramic processing methods – represents the formation of a spontaneous microscopic surface controlled on the nanoscale with atomic precision.

Further study revealed that the separation of the structure into two distinct phases was a result of the oxide separating into lithium rich squares and lithium poor stripes. By varying the amount of lithium and neodymium, two ingredients in the ceramic powder, engineers controlled the length and spacing of the alternating phases, thereby tuning the workbench upon which nanodevices could be built.

On a larger-than-atomic scale, the research extends science’s knowledge of the properties of a most common oxide structure type, currently used for superconducting materials, magnetoresistive materials and ferroelectrics.

“This study represents great potential for the use of standard ceramic processing methods for nanotechnology,” said Peter K. Davies, chair of the Department of Materials Science and Engineering at Penn. “The phase separation occurs spontaneously, providing two phases whose dimensions both extend into the nanometer scale. This unique feature could lead to its application as a template for the assembly of nanostructures or molecular monolayers.”

Source: University of Pennsylvania

Related stories:

Unique Material May Allow Capacitors to Store More Energy
Imagine an electric car with the same acceleration capability as a gas-powered sports car, or ultrafast rechargeable “batteries” that can be recharged a thousand times more than existing conventional batteries. According to physicists at North Carolina State University, all of these things are possible, thanks to their research on a polymer – or plastic material – that when used as a dielectric in capacitors may allow the capacitors to store up to seven times more energy than those currently in use.
Polymer electric storage, flexible and adaptable
(PhysOrg.com) -- The proliferation of solar, wind and even tidal electric generation and the rapid emergence of hybrid electric automobiles demands flexible and reliable methods of high-capacity electrical storage. Now a team of Penn State materials scientists is developing ferroelectric polymer-based capacitors that can deliver power more rapidly and are much lighter than conventional batteries.
Researchers explain odd oxygen bonding under pressure
Oxygen, the third most abundant element in the cosmos and essential to life on Earth, changes its forms dramatically under pressure transforming to a solid with spectacular colors. Eventually it becomes metallic and a superconductor. The underlying mechanism for these remarkable phenomena has been fascinating to scientists for decades; especially the origin of the recently discovered molecular cluster (O2)4 in the dense solid, red oxygen phase.
Superfluid-superconductor relationship is detailed
Scientists have studied superconductors and superfluids for decades. Now, researchers at Washington University in St. Louis have drawn the first detailed picture of the way a superfluid influences the behavior of a superconductor. In addition to describing previously unknown superconductor behavior, these calculations could change scientists' understanding of the motion of neutron stars.
New materials for microwave cookware that heats faster with less energy
You may soon be enjoying microwave popcorn and other 'nuked' foods and beverages faster than ever before, while saving on electricity. Researchers in Pennsylvania and Japan report development of new ceramic materials that heat up faster and retain heat longer than conventional microwave cookware while using less energy. Their report is scheduled for the August 26 issue of ACS' Chemistry of Materials.
Protection built to scale -- fish scale, that is
(PhysOrg.com) -- Scientists seeking to protect the soldier of the future can learn a lot from a relic of the past, according to an MIT study of a primitive fish that could point to more effective ways of designing human body armor.
Shells - a unique climate archive on the ocean floor
Most people who find a seashell during their summer holiday on the coast will probably not be aware that they have found a unique record of the climate. For Professor Bernd Schöne, however, these hard calcium shells provide a profound insight into the history of our earth and especially into the climate of the past.
Room temperature superconductivity: One step closer to the Holy Grail of physics
Scientists at the University of Cambridge have for the first time identified a key component to unravelling the mystery of room temperature superconductivity, according to a paper published in today's edition of the scientific journal Nature.

News discussion:

Nanotechnology news