New Design Strategy Can Help Improve Layered Superconducting Materials
October 14, 2019 | Tokyo Metropolitan UniversityEstimated reading time: 2 minutes
Scientists from Tokyo Metropolitan University have created a new layered superconducting material with a conducting layer made of bismuth, silver, tin, sulfur and selenium. The conducting layer features four distinct sublayers; by introducing more elements, they were able to achieve unparalleled customizability and a higher "critical temperature" below which superconductivity is observed, a key objective of superconductor research. Their design strategy may be applied to engineer new and improved superconducting materials.
Once an academic curiosity, superconductors are now at the cutting edge of real technological innovations. Superconducting magnets are seen in everyday MRI machines, particle accelerators for medical treatments, not to mention the new Chuo Shinkansen maglev train connecting Tokyo to Nagoya currently being built. Recently, a whole new class of "layered" superconducting structures have been studied, consisting of alternate layers of superconducting and insulating two-dimensional crystalline layers. In particular, the customizability of the system has garnered particular interest in light of its potential to create ultra-efficient thermoelectric devices and a whole new class of "high temperature" superconducting materials.
A team led by Associate Professor Yoshikazu Mizuguchi from Tokyo Metropolitan University recently created a bismuth sulfide based layered superconductor; their work has already revealed novel thermoelectric properties and an elevated "critical temperature" below which superconductivity is observed. Now, working with a team from the University of Yamanashi, they have taken a multi-layered version of the system, where the conducting layer consists of four atomic layers, and begun swapping out small proportions of different atomic species to probe how the material changes.
Starting with a conducting layer made of bismuth, silver and sulfur, they tried substituting some of the silver for tin. By varying the amount of silver, they were able to raise the critical temperature from 0.5K to above 2.0K. Interestingly, they found that this was accompanied by the disappearance of an anomaly in its resistivity at significantly higher temperatures. Though the reason behind this is not yet understood, it is clear that the addition of tin has significantly modified the electronic structure of the material. Furthermore, they took their best bismuth, silver, sulfur and tin combination and substituted some of the sulfur for selenium, a modification known to improve superconducting properties in their original bismuth sulfide material. Not only did they raise the critical temperature further to 3.0K, they found that the response to magnetic fields showed signatures of "bulk" superconductivity, providing clear proof that they could in fact access both the advantages of reduced dimensionality and bulk materials.
By changing the composition and number of layers, the team believe they are on the verge of achieving bottom-up engineering of new, tailored bismuth sulfide based superconducting materials.
Suggested Items
PCB Market Size to Grow by $29.06B from 2024-2028
05/17/2024 | PRNewswireThe global printed circuit board (PCB) market size is estimated to grow by USD 29.06 bn from 2024-2028, according to Technavio. The market is estimated to grow at a CAGR of over 6.6% during the forecast period.
epoxySet Launches EC-1015HP - High Temperature, Crack Resistant Epoxy Potting
05/13/2024 | epoxySetepoxySet introduces the EC-1015HP epoxy potting compound. This heat cure system is designed for temperature cycling from -55 to 180°C with significantly better crack resistance than traditional rigid epoxies. As a low viscosity encapsulant, it is used for large and small potting applications with fragile components.
New Book on Low-temperature Soldering Now Available
04/17/2024 | I-Connect007I-Connect007 is pleased to announce that The Printed Circuit Assembler’s Guide to… Low-temperature Soldering, Vol. 2, by subject matter experts at MacDermid Alpha Electronics Solutions, is now available for download.
The Chemical Connection: Reducing Etch System Water Usage, Part 1
04/05/2024 | Don Ball -- Column: The Chemical ConnectionWater conservation has become an important component of the overall system design for most manufacturing operations today. Changing climate conditions and increasing populations are beginning to strain the freshwater supplies in many areas of the country. As a result, as equipment suppliers, we see an increasing number of requests for options that reduce water usage in proposed wet processing systems. Etching systems tend to use more water because of the need for close temperature control to maintain steady etch rates and the rinsing requirements for complete removal of corrosive etchants from the surface of the product before the next process step. This column contains some simple suggestions for reducing water usage in etch systems that won’t strain the budget too much.
Indium’s Sze Pei Lim to Present on Semiconductor Packaging at ICEP Japan
04/02/2024 | Indium CorporationIndium Corporation’s Senior Global Product Manager for Semiconductor and Advanced Materials, Sze Pei Lim, is scheduled to present at the International Conference on Electronics Packaging (ICEP 2024).