Please use this identifier to cite or link to this item: https://www.um.edu.mt/library/oar/handle/123456789/18645
Title: Colossal magnetocaloric effect in magneto-auxetic systems
Authors: Dudek, Miroslaw
Wojciechowski, Krzysztof W.
Grima, Joseph N.
Caruana-Gauci, Roberto
Dudek, Krzysztof
Keywords: Phase transformations (Statistical physics)
Metamaterials
Magnetic fields
Elasticity
Issue Date: 2015
Publisher: IOP Publishing
Citation: Dudek, M., Wojciechowski, K. W., Grima, J. N., Caruana-Gauci, R., & Dudek, K. (2015). Colossal magnetocaloric effect in magneto-auxetic systems. Smart Materials and Structures, 24(8), 1-5.
Abstract: We show that a mechanically driven magnetocaloric effect (MCE) in magneto-auxetic systems (MASs) in the vicinity of room temperature is possible and the effect can be colossal. Even at zero external magnetic field, the magnetic entropy change in this reversible process can be a few times larger in magnitude than in the case of the giant MCE discovered by Pecharsky and Gschneidner in Gd5(Si2Ge2). MAS represent a novel class of metamaterials having magnetic insertions embedded within a non-magnetic matrix which exhibits a negative Poisson's ratio. The auxetic behaviour of the non-magnetic matrix may either enhance the magnetic ordering process or it may result in a transition to the disordered phase. In the MAS under consideration, a spin 1/2 system is chosen for the magnetic component and the well-known Onsager solution for the two-dimensional square lattice Ising model at zero external magnetic field is used to show that the isothermal change in magnetic entropy accompanying the auxetic behaviour can take a large value at room temperature. The practical importance of our findings is that MCE materials used in present engineering applications may be further enhanced by changing their geometry such that they exhibit auxetic behaviour.
URI: https://www.um.edu.mt/library/oar//handle/123456789/18645
Appears in Collections:Scholarly Works - FacSciChe
Scholarly Works - FacSciMet

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