IIT Mandi Researchers Observe Zero Resistance In Gold-Silver Nanostructures At High Temperatures

A team of researchers from Indian Institute of Technology (IIT) Mandi has found that nanomaterials made of gold embedded with silver show zero resistance to the flow of electric current through them, reports The Hindu.

According to the report, the phenomenon occurs at the relatively high temperatures, between 240 Kelvin and 275 Kelvin, that is, approximately between minus 33 degree Celsius and 2 degree Celsius.

“The resistance fluctuated as we lowered the temperature and suddenly fell below the limit of resolution of the apparatus on cooling below a critical temperature. As we repeated the heating and cooling, this critical temperature varied between 240 K and 275 K,” said CS Yadav from School of Basic Sciences, IIT Mandi, as reported by The Hindu.

However, the possibility of the group fabricating structures that are superconducting, a property of a material that allows electricity to pass through it with zero resistance, at relatively high temperatures could not be affirmed as out of the six gold-silver nanostructures samples that were studied, the team was able to see such a fall in resistance in only one sample.

The team also did not observe diamagnetism in the sample, another important property of the superconductor. A semiconductor turns into a diamagnet below a critical temperature and expels the magnetic flux from its insides. However, Vishwanath Balakrishnan, from the School of Engineering at IIT Mandi, who led the study along with Yadav, attributed the lack of diamagnetism to the low amount of material used for the study.

As per the report, the team was inspired by the work of Ashu Pandey and Dev Kumar Thapa of the Indian Institue of Science, Bengaluru, who had posted on ArXiv their observations on carefully fabricated nanostructures of silver embedded in gold.