Low Temperature Physics: 46, 764 (2020); https://doi.org/10.1063/10.0001537
Физика Низких Температур: Том 46, Выпуск 8 (Август 2020), c. 909-913 ( к оглавлению , назад )
Theory of giant magnetocaloric effect in the shape memory alloy undergoing magnetostuctural phase transition
Victor A. L’vov1,2, Anna Kosogor1, and Volodymyr A. Chernenko3,4
1Institute of Magnetism of the National Academy of Sciences of Ukraine and Ministry of Education and Science of Ukraine, Kyiv 03142, Ukraine
2Taras Shevchenko National University of Kyiv, Kyiv 01601, Ukraine
3BCMaterials & University of Basque Country, UPV/EHU, Bilbao 48080, Spain
4Ikerbasque, Basque Foundation for Science, Bilbao 48013, Spain
Received March 5, 2020, published online June 22, 2020
The theory of the giant conventional and inverse magnetocaloric effects (MCEs) is advanced on the basis of the theory of magnetism developed by A.I. Akhiezer, V.G. Bar’yakhtar, and S.V. Peletminsky in the classic monograph “Spin Waves”. The MCE in the shape memory alloy undergoing the first-order phase transition from the cubic ferromagnetic (FM) phase to the tetragonal antiferromagnetic (AFM) phase is considered. The agreement between the theoretical results and existing experimental data is demonstrated. It is argued that the alloys undergoing the phase transition to AFM phases with weak exchange interaction between the magnetic sublattices are promising for use in the magnetic refrigeration technique. The possibility of observation of the giant MCE in the layered magnetic structure with weak spin-exchange coupling between the FM layers is discussed.
Key words: metamagnetic shape memory alloy, martensitic transformation, specific heat, adiabatic temperature change.