Large Enhancement of Magnetocaloric and Barocaloric Effects by Hydrostatic Pressure in La(Fe0.92Co0.08)11.9Si1.1 with a NaZn13-Type Structure

Published

March 10, 2020

Author(s)

Jiazheng Hao, Fengxia Hu, Jian-Tao Wang, Fei-Ran Shen, Zibing Yu, Houbo Zhou, Hui Wu, Qingzhen Huang, Kaiming Qiao, Jing Wang, Jun He, Lunhua He, Ji-Rong Sun, Baogen Shen

Abstract

Solid state refrigeration based on caloric effect has been regarded as an attractive alternative to conventional gas compression technique. Boosting the caloric effect of a system to its optimum is a long-term pursuit. Here, we report enhanced magnetocaloric effect (MCE) and barocaloric effect (BCE) by hydrostatic pressure in La(Fe_0.92Co_0.08)_11.9Si_1.1 with NaZn₁₃-type structure. The entropy change δS_MCE is almost doubled under 11.31kbar, while the δS_BCE is more than tripled under 9kbar. Neutron powder diffraction (NPD) studies were performed to disclose the origin of such pressure-enhanced MCE and BCE, . The NPD results revealed that hydrostatic pressure sharpens the magnetoelastic transition and enlarges the volume change, δV/V, during the transition through altering the intra-icosahedral Fe-Fe bonds rather than the intericosahedral distances in the NaZn₁₃-type structure. First-principles calculations were performed, which supports the enlarged caloric effect related to the evolution of phase transition. Moreover, the enhanced lattice entropy change was calculated by Debye approximation, which is demonstrated to serve as a reliable way to evaluate BCE under a high pressure that DSC cannot reach. The present study proves that remarkable caloric effect enhancement can be achieved through tackling specific atomic environments by physical pressure, which may also be used to tailor other pressure related effects, such as controllable negative thermal expansion.

Citation

Chemistry of Materials

Volume

32

Issue

5

Pub Type

Journals

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Keywords

Magnetocaloric effect, barocaloric effect, neutron powder diffraction

Citation

Hao, J. , Hu, F. , Wang, J. , Shen, F. , Yu, Z. , Zhou, H. , Wu, H. , Huang, Q. , Qiao, K. , Wang, J. , He, J. , He, L. , Sun, J. and Shen, B. (2020), Large Enhancement of Magnetocaloric and Barocaloric Effects by Hydrostatic Pressure in La(Fe_0.92Co_0.08)_11.9Si_1.1 with a NaZn₁₃-Type Structure, Chemistry of Materials, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929397 (Accessed April 19, 2024)