Researchers at the U.S. Department of Energy (DOE)'s Oak Ridge National Laboratory (ORNL) have reported progress in fabricating advanced materials at the nanoscale. The spontaneous self-assembly of nanostructures composed of multiple elements paves the way toward materials that could improve a range of energy-efficient technologies and data storage devices.
ORNL Materials Science and Technology Division researcher Amit Goyal led the effort, combining theoretical and experimental studies to understand and control the self-assembly of insulating barium zirconium oxide nanodots and nanorods within barium-copper-oxide superconducting films.
"We found that a strain field that develops around the embedded nanodots and nanorods is a key driving force in the self-assembly," says Goyal, a UT-Battelle Corporate Fellow. "By tuning the strain field, the nanodefects self-assembled within the superconducting film and included defects aligned in both vertical and horizontal directions."
The controlled assembly within the superconducting material resulted in greatly improved properties, Goyal says, including a marked reduction in the material's anisotropy, or directional dependence, desired for many large-scale, high-temperature superconductivity applications.
The strain-tuning the team demonstrated has implications in the nanoscale fabrication of controlled, self-assembled nanostructures of multiple elements, with properties suitable for a range of electrical and electronic applications, including multiferroics, magnetoelectrics, thermoelectrics, photovoltaics, ultra-high density information storage, and high-temperature superconductors.
"Such nanocomposite films with different overall composition, concentration, feature size, and spatial ordering can produce a number of novel and unprecedented properties that are not exhibited in individual materials or phases comprising the composite films," Goyal says.
The research was reported in Advanced Functional Materials.
Source: Oak Ridge National Laboratory