Thermal rectification based on phase transition materials

Significance 

Significant loss of energy occurs every day in industrialized countries. For instance, in the United States alone, over 3000 TW of waste energy is lost annually. Going with the current trends, future waste energy loss is expected to escalate owing to continuous growth in the manufacturing sector. Interestingly, such huge losses are equivalent to billions of the oil barrel, that can be used in meeting the global energy demands. To this end, reclaiming the lost waste heat have attracted significant attention of researchers, as a way of solving the global energy crisis. Energy scientists proposed developing solid waste thermal devices as a potential and promising solution for recovering the waste heat.

Among the available devices, one stands out. A thermal diode which only allows heat flow in one direction has a great potential for efficient energy harvesting and heat controlling. Consequently, thermal rectification can be achieved not only at bulk scale but also at nanoscale levels. Recently, phase change materials have been used for controlling thermal flux due to their phase transition capability. This further permit control of the thermal conductivity either in the first order or second order transitions. However, thermal diodes based on organic phase transition materials have exhibited low thermal rectification factors. Therefore, the need to maximize their rectification factors to enhance their performance in various systems is highly recommended.

Recently, the Group of Embedded Nanomaterials for Energy Scavenging (GENES group) headed by Professor Jaime Alvarez Quintana from Research Center for Advanced Materials S.C. giving continuity to their pioneering works of thermal rectification based on phase transition materials* (CIMAV) designed and developed a thermal diode based on first and second order phase transition materials. Specifically, neopentylglycol and gadolinium were utilized as first and second order phase transition materials respectively. Their research work co-authored by Dr. J. Leon, and Dr. J. Martinez is currently published in Journal of Materials Science.

In brief, the design entailed a composite of neopentylglycol and gadolinium transition materials which was used to validate the design. Next, the influence of both the transitions and temperature on the rectification factors were examined. Eventually, the authors investigated the feasibility of using the combined effects in fabricating high-performance thermal rectifiers.

The authors recorded a higher thermal rectification factor of 1.45 for the hybrid device as compared to 1.2 recorded in the initial devices that were based only on neopentylglycol. This was attributed to the manifestation of the influence of the transitions along the asymmetric temperature in the heat transfer axis of the thermal device as well as the molecular transformations in neopentylglycol and magnons deactivation in gadolinium. Furthermore, the developed model based on the continuum heat conduction laws indicated similarities in the experimental and predicted behaviors thus showing the accuracy of the model.

In summary, Professor Jaime Alvarez Quintana and the research team successfully fabricated a hybrid thermal diode based on the transition materials. To actualize their study, the results were further analyzed using finite element analysis based on ANSYS, from which the concept proved efficient for developing high-performance thermal rectifiers. In general, the CIMAV study will advance the efforts to reclaim waste heat and use to it produce electricity, an approach that will significantly enhance energy production and utilization.

Thermal rectification based on phase transition materials - Advances in Engineering
Thermal diode based on, a) lattice phase transitions, and b) magnetic phase transitions of heterojunctions of Non-PCM/PCM. In first-order transitions, the thermal conductivity can be controlled via a change in the vibrational frequency of atoms or molecules in the lattice at the transition temperature Tt, whereas in second-order transitions the thermal conductivity of ferromagnetic materials can be controlled via deactivation of magnons at the transition temperature Tcurie. In both cases, phase-change materials (PCM) with either first or second order phase transition can exist in two states with different thermal conductivities. Therefore, depending on direction of the applied heat flux both systems will present different effective thermal conductivities. So that, once the interface temperature Ti overcomes the transition temperature, a nonlinear thermal transport will be present.

About the author

Jaime Alvarez is professor of Physics in the department of Physics of Materials at the Centro de Investigacion en Materiales Avanzados S.C. Unidad Monterrey, Mexico (CIMAV S.C.). He received the Ph.D. degree in Physics of Materials from Universitat Autonoma de Barcelona in 2009, and was a visiting professor in the Centre for IC Failure Analysis & Reliability (CICFAR) at the National University of Singapore in 2016. From 2009 to date, he has served as researcher at CIMAV S.C. where he is currently doing research on a variety of topics related to thermal transport in low dimensional systems with applications to thermoelectrics and solid state thermal devices.

In 2013, his research group was pioneering on proponing phase-change materials with first and second order phase transitions for thermal rectification. Currently, he holds National Research System level II, and he has been awarded with grants from the Mexican Council for Science and Technology (CONACYT) under the programs for Fundamental Research (CB-130124, CB-241597) and National Issues (PN-1358) to lead projects in the field of thermal energy harvesting and management.

References

Leon-Gil, J., Martinez-Flores, J., & Alvarez-Quintana, J. (2018). A hybrid thermal diode based on phase transition materials. Journal of Materials Science, 54(4), 3211-3221.

Go To Journal of Materials Science

 

*Martınez-Flores, J., Licea-Jimenez, L., Perez Garcia, S., & Alvarez-Quintana, J. (2013). Magnon-mediated thermal rectification with forward-bias and breakdown temperatures. Journal of Applied Physics, 114, 104904.

*Garcia-Garcia, K., & Alvarez-Quintana, J. (2014). Thermal rectification assisted by lattice transitions. International Journal of Thermal Sciences, 81, 76-83.

*Martinez-Flores, J., Varshney, D., & Alvarez-Quintana, J. (2018). Thermal rectification via sequential deactivation of magnons. Applied Physics Letters, 113, 264102.

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