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Superconductivity

Scientists have found that in addition to chemical manipulation, superconductivity can be induced by high pressure in high-temperature superconductors. The high critical temperatures on record were first measured here (164 K). 

A broad range of studies of the physical and chemical properties of solids can be now conducted in situ at high pressures to several hundred gigapascals. When pressure is increased on solids, interactions between atoms increase, in some cases radically altering a material's physical and chemical properties. One striking example of this behavior is demonstrated by superconductivity in compressed elements (sulfur, hithium, boron). In contrast, changing interatomic distances by varying composition is restricted by the discrete nature of chemical elements, and tuning by temperature is complicated by thermal excitations (i.e., vibrations) and ultimately the melting and boiling points of the material. Thus, the application of pressure provides an ideal means to carefully tune electronic, magnetic, structural and vibrational properties for a wide range of applications. For example, the highest Tc's are found under pressure, as demonstrated by our work on high-Tc cuprates. Exploration of the pressure variable is increasing the number of known materials. Such phenomena, as re-emerging superconductivity in Fe-based superconductors, demonstrate the potential of high pressure to create new superconducting materials. Very precise pressure tuning allows observation of the details of the pressure-induced insulator-metal transitions and even more subtle changes in the electronic structure.

 

 

Record high Tc at 164K in Hg-based high-Tc triple-layer material Superconductivity in elements

Record high Tc at ~140K in Bibased high-Tc material Re-emerging superconductivity