Friday, September 18, 2009

"MATERIALS: Strain engineering aims for room-temp superconducting"

Room-temperature superconductors could someday be realized by a new class of material called correlated electron materials which change from insulators to semiconductors to conductors by applying external strain. When coupled to a piezoelectric material, the new correlated electron materials could have their function changed on-the-fly. Look for correlated electron materials to begin appearing in devices within five years. R.C.J.

Strain-correlated electron materials can be conductors, semiconductors or insulators depending on how much strain is engineered into their structure. As a new type of transition-metal oxide, correlated electron materials could allow the selective placement of strain to alter the spatial arrangement of its crystalline lattice, according to researchers at Lawrence Berkeley National Laboratory. The Energy Department lab recently created structural irregularities called phase inhomogeneity in correlated electron materials that could someday enable colossal magnetoresistance, and perhaps even room-temperature superconductivity.Correlated electron materials, as the name implies, exhibit correlated electron capabilities at room temperature that otherwise might require a phase change, such as by super cooling a superconducting material. By engineering the right kind of strain into a correlated electron material, designers could theoretically endow them with extraordinary room-temperature characteristics.