Materials Prediction Scores a Hit

Had the great American philosopher Yogi Berra been a condensed matter physicist, he might have said “It’s difficult to make predictions, especially about superconductivity.” Predictions about a material’s structure and even more so its function have been goals of materials research for a long time, but the track record for predicting that a given compound will superconduct is notoriously bad [1]. Fortunately, advances in the fidelity and resolution of electronic structure calculations are beginning to change this trend [2]. In fact, the White House’s Materials Genome Initiative [3] represents a recognition that with recent advances in computational capability and materials models, such breakthroughs are possible and, in fact, likely probable. In a paper in Physical Review Letters, Huiyang Gou at the University of Bayreuth, Germany, and colleagues [4] describe a success story in the search for predictability. They report the observation of superconductivity in iron tetraboride (FeB4) at approximately 3 kelvin (K). Not only did they find superconductivity where electronic structure calculations told them to look, they used high-pressure synthesis techniques to discover a compound that wasn’t readily apparent in nature. Further, the resulting compound, orthorhombic FeB4, turns out to be very mechanically hard as well as superconducting, thus possessing two desirable traits.