Large rotating magnetocaloric effect in the orthorhombic DyMnO3 single crystal

Review of the Magnetocaloric Effect in RMnO3 and RMn2O5 Multiferroic Crystals

“…The RMnO3 (R = rare earth) manganites have generated worldwide interest due to their rich physical properties and potential implementation in a wide range of applications going from spintronics such as four state memory systems [37] to magnetocaloric refrigeration [20][21][22][23][24]26,27]. In these highly frustrated multiferroics, the magnetic, electric and crystallographic structures are markedly coupled and strongly depend on the rare earth element size (rR) [22,27,[65][66][67][68].…”

“…On the other hand, the orthorhombic DyMnO3 shows a meaningful inverse (or negative) magnetocaloric effect at temperatures below 6 K. This was mainly attributed to the antiferromagnetic ordering of Dy 3+ magnetic moments in this temperature range. In fact, under the effect of an external magnetic field, the AFM phase transforms into a less ordered "ferromagnetic" one increasing then the material's magnetic entropy [24,26]. In contrast to the orthorhombic phase, the h-DyMnO 3 crystal unveils its easy axis along the c-orientation, while the hard-direction is parallel to the ab-plane.…”

“…In addition, as claimed by Barclay et al [18], a large scale utilization of hydrogen as a source of energy will result in better energy security with major environmental, economic, and social benefits. In this context, several cryomagnetocaloric materials have been proposed [19][20][21][22][23][24][25][26][27][28]. Following this, Matsumoto et al [29,30] unveiled a reciprocating magnetic refrigerator dedicated to hydrogen liquefaction that uses the Dy 2.4 Gd 0.6 Al 5 O 12 garnet as refrigerant.…”

“…Especially, some of these systems show a strong coupling between magnetism and ferroelectricity which provides an additional degree of freedom regarding the design of magnetoelectric effect-based machines [30][31][32][33][34][35][36][37][38][39][40]. On the other hand, the investigation of their magnetocaloric properties has unveiled a great potential for application in magnetic refrigeration at low temperature regime [19][20][21][22][23][24][25][26][27][28]. This means that more than one task can be achieved by only using a single RMn 2 O 5 or RMnO 3 material which is of great interest from an economical point of view.…”

Analysis of the Anisotropic Magnetocaloric Effect in RMn2O5 Single Crystals

“…However, the search for materials with excellent magnetocaloric properties in the temperature range from about 2 to 30 K is of great interest from fundamental, practical, and economical points of view, due to their potential use as refrigerants in several low temperature applications such as the space industry, scientific instruments, and gas liquefaction [14][15][16][17][18][19][20][21][22][23][24][25]. On the other hand, the development of new designs that can render magnetic cooling more competitive is also a key parameter for the commercialization of this emergent technology.…”