Liquid Metal-Based Magnetorheological Fluid with a Large Magnetocaloric Effect

Yongyu Lu; He Zhou; Henan Mao; Shousheng Tang; Lei Sheng; Hu Zhang; Jing Liu

doi:10.1021/acsami.0c11153

Liquid Metal-Based Magnetorheological Fluid with a Large Magnetocaloric Effect

ACS Appl Mater Interfaces. 2020 Oct 28;12(43):48748-48755. doi: 10.1021/acsami.0c11153. Epub 2020 Oct 19.

Authors

Yongyu Lu¹, He Zhou², Henan Mao³, Shousheng Tang¹, Lei Sheng¹, Hu Zhang², Jing Liu¹

Affiliations

¹ Key Laboratory of Cryogenics and Beijing Key Laboratory of Cyro-Biomedical Engineering, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
² School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
³ Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.

PMID: 33070606
DOI: 10.1021/acsami.0c11153

Abstract

Herein, liquid metal and Mn_0.6Fe_0.4NiGe_0.54Si_0.46 particles with a large magnetocaloric effect are adopted to prepare a novel magnetocaloric suspension named liquid metal-based magnetorheological fluid (LM²RF), which can well solve the problems of brittleness, low thermal conductivity, and poor machinability in classical magnetocaloric materials. The low melting point and high boiling point of liquid metal could significantly widen the operating temperature range of such a fluid. As a carrier, the high thermal conductivity, low viscosity, and large density of liquid metal display advantageous to heat transfer. The maximum loading fraction is 19.5 wt %, while LM²RF features the liquid state. A series of tests are conducted to investigate the alloying behavior in LM²RF. It is found that galinstan will react with Mn_0.6Fe_0.4NiGe_0.54Si_0.46 particles and form MnGa alloy. However, the reaction rate is very slow and the generated MnGa alloy is passivating. Consequently, the quantity of MnGa alloy is too sparse to affect the magnetocaloric performance of LM²RF. Overall, the LM²RF exhibits a large MCE at around room temperature with a lower magnetic hysteresis loss, and the transition temperature (T_m) remains constant in 60 days. This work demonstrates the outstanding performance of LM²RF and provides a promising alternative to MCE materials for practical magnetic refrigeration.

Keywords: alloying mechanism; liquid metal-based magnetorheological fluid; loading fraction; magnetocaloric effect; maximum magnetic entropy change.