Room-temperature superconductors

Our research into the fundamental properties of superconducting materials could identify a new superconductor that carries current without extensive cooling.

Although all superconductors can transport electricity without loss, how well they do so varies from one material to the next. Superconductivity depends on intrinsic properties of a material, such as crystal structure, defects, and dopant atoms, as well as external conditions like temperature, pressure, and magnetic field.

Characterising the influence of these factors helps to advance our understanding of what makes a material a superconductor and may one day lead to the development of room-temperature superconductors.

The science

In contrast to the simple metallic low-temperature superconductors for which a Nobel-prize-winning theory exists, scientists are still trying to understand the physics of the complex oxide high-temperature superconductors. Fundamental studies of the factors that affect superconductivity are key to this decades-long global effort.

To do these fundamental studies, Paihau—Robinson Research Institute hosts a suite of advanced instruments capable of performing various transport, thermodynamic, and optical measurements down to very low temperatures and in high magnetic fields and pressures. In addition, our investigators also have access to a wide range of other domestic and international facilities through an extensive network of collaborators. Interpretation of data is supported by in-house expertise in computational modelling and analysis.

Impact and potential

Characterisation studies are essential for optimising new classes of superconducting materials. The maximum operating temperature (Tc) of the first high-temperature superconductor discovered in 1986 was just 35 K. By 1993 Tc had increased to 133 K in a related compound, and this could be boosted further to 160 K by the application of pressure.

But operating temperature is just one of many parameters of interest. For example, we have made many important contributions in understanding how to maximise the amount of electric current that a superconductor can carry, which is arguably more important for applications.

So, will we ever find a room-temperature superconductor with a Tc near 293 K? Without knowledge of the mechanism behind high-temperature superconductivity, new materials are only sporadically discovered by trial and error. Identifying the mechanism should help us narrow the search for new superconductors and might even allow us to design one from scratch. Testing models against data from characterisation measurements provides a path towards that goal.

Capabilities

• Superconducting quantum interference device (Squid)—an extremely sensitive magnetometer
• Physical properties measurement. Thermal conductivity, resistance, specific heat. Capability to measure down to -270°C and in high magnetic fields—up to 9 teslas
• Strong capability in computational modelling

The people

Dr James Storey specialises in the physics of high-temperature superconductors, with a focus on computational modelling of their distinctive electronic properties. He has strong links with Cambridge University and thrives on the stimulating environment that the Robinson Research Institute provides.