Through several refinements to the tried and true method of pulsed laser deposition, Oak Ridge National Laboratory researchers have a new way to synthesize materials and conduct basic studies vital to creating new ones. By continuously monitoring the growth process and precisely controlling the amount of material deposited for each layer, researchers were able to grow artificial oxide crystals up to 5,000 atomic layers thick. They did this while preserving a perfectly flat surface. This unprecedented work involved atomic-scale control of individual layers of barium titanate, strontium titanate and calcium titanate. Hans Christen of the lab's Condensed Matter Sciences Division noted that the method can be used to produce materials lacking the symmetry found in almost all naturally occurring materials and can be designed in advance to exhibit specific desired physical properties. Consequently, this is a significant step toward long-sought designer materials expected to have a wide range of applications, particularly as sensors and switches and in the semiconductor industry. Funding for this research, which is published in the Jan. 27 issue of Nature, is provided by ORNL's Laboratory Directed Research and Development program.
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