Magnetic ordered structure dependence of magnetic refrigeration efficiency

Abstract

We have investigated the relation between magnetic ordered structure and magnetic refrigeration efficiency in the Ising model on a simple cubic lattice using Monte Carlo simulations. The magnetic entropy behaviors indicate that the protocol, which was first proposed in [Appl. Phys. Lett. 104, 052415 (2014).], can produce the maximum isothermal magnetic entropy change and the maximum adiabatic temperature change in antiferromagnets. Furthermore, the total amount of heat transfer under the proposed protocol reaches a maximum. The relation between measurable physical quantities and magnetic refrigeration efficiency is also discussed. FIG. 2. (Color online) Schematics of ordered magnetic structures in the Ising models on a simple cubic lattice. The signs of the magnetic interactions J ab and Jc and the wave vector k, when the lattice constant is set to unity, are shown for each magnetic structure. These figures were drawn by VESTA 84 .

Applicability of scaling behavior and power laws in the analysis of the magnetocaloric effect in second-order phase transition materials

“…The Wang-Landau method is one of the multicanonical methods, which can directly obtain the density of states. Then, the behavior of magnetic entropy can be calculated with high accuracy [16,17]. We confirmed that the magnetic entropies for L = 8, L = 12, and L = 16 are almost collapsed.…”

“…There are some interesting papers in which MC simulations are used with different materials like Gd(Si x Ge 1−x ) 4 [11], (Gd x Tb 1−x ) 5 Si 4 [12], and several Heusler alloys [13][14][15]. Recently, a new type protocol of the MCE was proposed in theoretical studies based on the MC methods [16,17]. On the other side, DFT is less used in this research field, although it has been used to describe both the structural and the magnetic phase transitions in some rare-earth intermetallic pseudo-alloys exhibiting a giant MCE [18][19][20][21][22][23], and there have been very few attempts to describe the MCE of materials from first principles by only using DFT.…”

Magnetic structures of nearly isostructural Tb3RuO7 and Nd3RuO7 : Appearance of a partially disordered state o

“…We explain the physical meaning of the relation between − S m,max and T max . Tamura et al calculated magnetic entropy changes of three-dimensional magnets [42]. The magnetic entropy change is large at around the magnetic transition temperature (T c ) and increases with increase in H/J (∼H/T c ).…”

Magnetocaloric Effect in an Antidot: The Effect of the Aharonov-Bohm Flux and Antidot Radius

“…From a fundamental point of view, the magnetocaloric effect (MCE) consists of the temperature variation of a material due to the change of a magnetic field to which it is subjected [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Nowadays the research of the MCE effect reawakens a strong interest in the scientific community again [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ]. We highlight the works associated with high-temperature caloric materials [ 21 ], antiferromagnetic and ferromagnetic interactions [ 8 , 15 , 29 , 30 ], heavy lanthanides [ 31 ], Fe-Rh alloys [ 32 ], among others.…”