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Origin and Tuning of the Magnetocaloric Effect in the Magnetic Refrigerant Mn1.1Fe0.9(P0.8Ge0.2)



Danmin Liu, Ming Yue, Jiuxing Zhang, T. M. McQueen, Jeffrey Lynn, Xiaolu Wang, Ying Chen, Jiying Li, R. J. Cava, X. Liu, Zaven Altounian, Qingzhen Huang


Neutron-diffraction and magnetization measurements have been carried out on a series of samples of the magnetorefrigerant Mn1+yFe1−yP1−xGex. The data reveal that the ferromagnetic and paramagnetic phases correspond to two very distinct crystal structures, with the magnetic-entropy change as a function of magnetic field or temperature being directly controlled by the phase fraction of this first-order transition. By tuning the physical properties of this system we have achieved a magnetic-entropy change [magnetocaloric effect (MCE)] for the composition Mn1.1Fe0.9P0.80Ge0.20 that has a similar shape for both increasing and decreasing field, with the maximum MCE exceeding 74 J/kg K—substantially higher than the previous record. The diffraction results also reveal that there is a substantial variation in the Ge content in the samples which causes a distribution of transition temperatures that reduces the MCE. It therefore should be possible to improve the MCE to exceed 100 J/kg K under optimal conditions.


crystal structure, first-order transition, magnetic refrigerant, magnetization, magnetocaloric effect, magnetoelastic effect


Liu, D. , Yue, M. , Zhang, J. , McQueen, T. , Lynn, J. , Wang, X. , Chen, Y. , Li, J. , Cava, R. , Liu, X. , Altounian, Z. and Huang, Q. (2009), Origin and Tuning of the Magnetocaloric Effect in the Magnetic Refrigerant Mn1.1Fe0.9(P0.8Ge0.2), Science, [online],, (Accessed July 17, 2024)


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Created January 26, 2009, Updated March 18, 2024