When discovered in 1938, the crystal ammonium dihydrogen phosphate (ADP) was observed to exhibit unusual electrical properties. A Florida State University chemist, Naresh S. Dalal, and three colleagues of the Universidad Nacional de Rosario in Argentina used the supercomputer at FSU's Supercomputer Computations Research Institute to determine why the crystal behaves the way it does.
ADP is commonly used in computer memory devices, fiber optic technology, lasers, and other electro-optic applications. For nearly 70 years scientists have remained perplexed by ADP's frequent display of antiferroelectricity, in which one layer of molecules in a crystal has a positive and a negative pole but in the next layer the charges are reversed.
Dalal's team used the supercomputer to theoretically alter the angles of ADP's ammonium ions and measure the effects on the crystal's electrical charge. They found that the position of the ammonium ions in the compound as well as the presence of stresses or defects in the crystal determine whether it behaves in a ferroelectric or antiferroelectric manner. The team's research furthers understanding of how to design materials with both ferroelectric and antiferroelectric properties, which could open new doors for computer memory technology and play a role in the development of quantum computers.