Webinar title: Research and Development of Sub-Kelvin Refrigerants and Equipment
Speaker: Prof. Tao Liu
Webinar time：Oct. 19th 2025 (Sunday), 10:00
Venue：Room 200, New Environmental Building
Inviter：Tianfu Wang
Abstract:
An integrated physical property measurement system for the sub-Kelvin temperature range has been developed based on adiabatic demagnetization refrigeration technology. This addresses the urgent demand for extreme low-temperature environments in fields such as condensed matter physics and further drives transformative advancements in application areas like quantum technology. Adiabatic demagnetization refrigeration represents a key technology for achieving self-reliance and control by reducing dependence on scarce resources like He-3. However, existing cryogenic magnetic refrigeration materials suffer from issues such as low magnetic entropy change and narrow operating temperature ranges, severely limiting refrigeration performance and application scenarios. We pioneered the introduction of spin-frustrated molecular design, successfully resolving the bottleneck of achieving both high magnetic entropy density and a broad temperature range. The material's magnetic entropy change density exceeds that of the optimal commercial material GGG by more than twofold, while the low-temperature limit expands from 400 mK to below 50 mK. To maximize material performance, we proposed an axial thermal bus architecture and a new method for controlling hysteretic nonlinear responses based on property matching principles. This led to the development of core components such as high-thermal-conductivity salt columns and high-speed thermal switches, achieving a mass-specific cooling power exceeding existing systems by a factor of two and enabling continuous temperature control from 50 mK to 4 K. A modular testing interface was constructed for extreme low-temperature environments, developing multi-physics field interaction control methods. This enabled a leap from technical validation to an extreme low-temperature application platform, providing a practical and usable extreme low-temperature platform for fields such as condensed matter physics and deep space exploration.
About the speaker:
Tao Liu, Professor at Dalian University of Technology, doctoral supervisor, and current Dean of the School of Chemical Engineering. Recipient of the National Natural Science Foundation of China's Outstanding Young Scientist Fund. His research focuses on externally field-responsive magnetic materials and in-situ characterization equipment, yielding a series of innovative achievements in photo-responsive magnetic materials and in-situ testing devices, cryogenic magnetic refrigeration equipment, and magnetic catalytic materials. His research has been published in prestigious journals including Nat. Chem., Acc. Chem. Rev., Nat. Commun., Angew. Chem. Int. Ed., Chem. Sci., and Natl. Sci. Rev. He has received the Chinese Chemical Society Young Chemist Award, the First Prize in Natural Sciences from Liaoning Province, and the First Prize in Science and Technology from the Chinese Society for Analytical Chemistry.