Magnetism in Iron-Based Superconductors Better Understood
One day we may use electrical wires and cables capable of transmitting currents without resistance. The key to this future is understanding superconductivity, the phenomenon that enables it. Researchers at Oak Ridge National Laboratory and Vanderbilt University have recently made an interesting discovery concerning iron-based superconductors that challenges some long held beliefs.
Superconductivity arises in certain materials when they are brought down below some critical temperature. For the earliest superconductors, this temperature was just above absolute zero, but since then we have discovered high-temperature superconductors that have critical temperatures significantly higher, though still far from room temperature. Some of these superconductors are iron-based materials, which was unexpected initially as these materials also have magnetic properties. Large-range magnetism is known to suppress superconductivity, but now it has been discovered that local magnetic moments do not disrupt it In fact these isolated areas of magnetism within the material may assist superconductivity, as they are at their maximum when superconductivity is. The researchers also discovered that the number of electrons in the moments was the same for different kinds of iron-based superconductors, though their distributions differed.
Beyond the potential for understanding superconductivity better, this research could also have an impact on other technological materials and devices. To do the study, the researchers had to develop a way to measure the local moments, which had not been done before as previous research always looked at the bulk average.
Source: Oak Ridge National Laboratory