Fabrication of magnetocaloric La(Fe,Si)13 thick films

Abstract

La(Fe,Si)13-based compounds are considered to be very promising magnetocaloric materials for magnetic refrigeration applications. Many studies have focused on this material family but only in bulk form. In this paper we report on the fabrication of thick films of La(Fe,Si)13, both with and without post-hydriding. These films exhibit magnetic and structural properties comparable to bulk materials. We also observe that the ferromagnetic phase transition has a negative thermal hysteresis, a phenomenon not previously found in this material but which may have its origins in the availability of a strain energy reservoir, as in the cases of other materials in which negative thermal hysteresis has been found. Here, it appears that the substrate acts to store strain energy. Our exploratory study demonstrates the viability of thick films of the La(Fe,Si)13 phase and motivates further work in the area while showing that additional perspectives can be gained from reducing the dimensionality of magnetocaloric materials in which the magneto-volume effect is large. _______________________________________________ a)

Atomic‐resolution Interfacial Microstructure and Thermo‐electro‐magnetic Energy Conversion Performance of Gd/Bi0.5Sb1.5Te3 Composites

“…relative cooling power (RCP) are the important parameters to evaluate the MC performance. The most widely investigated room-temperature MC materials include Gd and its alloys, Gd 5 (Si x Ge 1-x ) 4 , LaFe 13-x Si x , MnAs, MnFeP x As 1-x , NiMnGa, and MnCoGe, et al [23][24][25][26][27][28][29][30] Among these materials, Gd is the most commonly used MC material in many active magnetic regenerators due to its sizable ΔS M near room temperature and small magnetic hysteresis. [31] Nevertheless, the inefficient heat exchange between the working fluid and MC material limits the cycle frequency and leads to a low cooling power density.…”

Inverse magnetocaloric effect in synthetic antiferromagnets

“…The giant MCE, later observed also in transition-metal [7][8][9] and Heusler-type alloys [10,11], is due to a field-induced spin rearrangement in the vicinity of the magnetic phase transition, which is often accompanied by a first-order structural phase transition [12][13][14]. Other novel approaches to enhancing the MCE are based on the finite-size effects in thin films and multilayers [2,15,16] and a family of spin-caloritronic effects in heavy-metal/ferromagnet based nanostructures [17,18].…”