A magnetocaloric composite based on molecular coolers and carbon nanotubes with enhanced thermal conductivity

Abstract

Improved performance of molecular cryogenic coolers is achieved through a hybrid composite material with increased thermal conductivity.

Magnetocaloric Effect and Thermal Conductivity of a 3D Coordination Polymer of [Gd(HCOO)(C2O4)]n

“…Owing to the fact that thermal conductivity properties of the magnetic coolant is one of the crucial factors in the refrigeration, , the thermal conductivity for 1 (Figure ) was investigated using steady-state method in the temperature range from 2 to 8 K. Notably, H -grease was employed as the linker between them to avoid thermosteresis compared to the direct contact between sample and copper in the process. With temperature decrease, the thermal conductivity of 1 remarkably decreased from 43.7 W m –1 K –1 to 4.7 W m –1 K –1 , showing the same monotonic decrease as GGG in the temperature range.…”

“…However, among a large number of reported magnetic coolants, very few magnets have magnetic entropy changes (−ΔS m ) > 30 J kg −1 K −1 at ΔH = 2 T and T < 2 K. 23 In addition to the magnetic entropy changes of magnetic coolants, the thermal conductivity of magnetic coolants is also crucial to practical application of magnetic refrigeration. This is because excellent thermal conductivity of magnetic coolants not only can effectively improve the heat exchange rate, especially at very low temperature, 24 in the process of adiabatic demagnetization and adiabatic magnetization but also can significantly enhance the heat exchange efficiency of the magnetic refrigeration cycle. However, little attention has been paid to this important factor.…”

A Magnetocaloric Glass from an Ionic‐Liquid Gadolinium Complex

“…In other words, magnetocaloric glass‐forming ILs constitute new single‐molecule metal‐organic objects that are appealing for material science research and also open applicative perspectives in the field of magnetocaloric “thermal greases”. Due to experimental requirements, heat transfer studies on MCMs remain extremely rare to this day, [31] and we hope our contribution provides impetus for designing such studies on molecular MCMs developed as Ionic Liquids.…”

Exchange-Bias Quantum Tunneling of the Magnetization in a Dysprosium Dimer

“…Since the discovery of the slow relaxation characteristics in metal-based molecules, better known as single-molecule magnets (SMMs), these molecules have been extensively explored leading to the observation of several other quantum phenomena, such as quantum tunneling of the magnetization − (QTM), quantum coherence, Berry Phases, quantum oscillations, − among others. , Due to the bewildering quantum mechanical properties, SMMs have been proposed in several futuristic applications such as molecular coolers, − data storage devices, ,− quantum bits for quantum computing, − quantum simulation, , and quantum sensing …”