Large Magnetic Entropy Change in Dy$_{1-x}$Ho$_{x}$Ni$_{2}$B$_{2}$C ($x = 0{\mbox{--}}1$) Superconductors

Abstract

The magnetocaloric effect in antiferromagnetic superconductors Dy1-xHoxNi2B2C (x = 0, 0.3, 0.5, 0.7, and 1) has been studied. The magnetic transition temperature TM as well as the temperature of the maximum magnetic entropy change (-ΔSMmax) gradually shift to low temperature with increasing x, while the values of -ΔSMmax remain at almost the same high value. The observed large magnetic entropy is related to a field-induced first-order metamagnetic transition from antiferromagnetic to ferromagnetic state. The large values of ΔSM and high relative cooling power with tuneable TM indicate that Dy1-xHoxNi2B2C could be used for low-temperature magnetic refrigeration.

Magnetocaloric effect in metamagnetic borocarbide DyNi2−xAxB2C (A=Co and Cr) compounds

“…4 for DyNi 2 − x A x B 2 C (A = Co and Cr, x = 0.1 and 0.2). For magnetic field changes of 1 and 2 T, − S M is negative (inverse MCE) below the transition temperature, and changes to positive with increasing temperature, this behavior is similar to that of the recently reported Dy 1 − x Ho x Ni 2 B 2 C [17] and RNi 2 B 2 C (R = Dy, Ho, and Er), [18] compounds which can be understood in terms of the FM-AFM phase coexistence and the variation in the ratio of these phases under different magnetic fields. A x B 2 C system with a magnetic field change of 7 T, respectively.…”

“…3 (c) and (d), respectively. A clear negative slope at low temperature and low magnetic field region can be observed, indicating the first order magnetic phase transition for DyNi 2 − x A x B 2 C (A = Co and Cr, x = 0.1 and 0.2) compounds, which is similar to those reported in GdCo 2 B 2 [21] and RNi 2 B 2 C (R = Dy, Ho, and Er) [17] compounds.…”

“…Fig. 2 shows the magnetic isothermals on increasing (open symbols) and decreasing (filled symbols) field for DyNi 2 − x A x B 2 C (A = Co and Cr, x = 0.1 and 0.2) at 2 K. Although a noticeable hysteresis was observed in Dy 1 − x Ho x Ni 2 B 2 C system [17] at low temperatures, the hysteresis is ignorable for all the present DyNi 2 − x A x B 2 C which is beneficial for application, i.e. similar to substitution of Tm for Dy [19], Ni site substitution of Co or Cr also can effectively reduce (even eliminate) the magnetic hysteresis of DyNi 2 B 2 C. The saturation magnetization decreases gradually with increasing Co and Cr content x.…”

“…For the Dy, Ho, Er and Tm systems, superconductivity coexists with magnetic order [11][12][13][14][15][16]. Very recently, giant/large MCEs in Dy 1 − x Ho x Ni 2 B 2 C (x = 0-1) [17] and RNi 2 B 2 C (R = Dy, Ho, and Er) [18] compounds have been reported. The observed magnetocaloric effect in RNi 2 B 2 C system is related to a field-induced first order metamagnetic transition from antiferromagnetic to ferromagnetic state.…”

Magnetic properties and magnetocaloric effect in quaternary boroncarbides compound ErNiBC

“…The magnetocaloric effect (MCE) in various materials has been investigated extensively for potential magnetic materials that can be used as magnetic refrigerants in the last two decades [1][2][3][4][5][6][7][8][9][10]. Magnetic refrigeration technology based on MCE has many advantages, such as higher energy efficiency and more environmental friendly compare to the conventional gas compression/ expansion refrigeration technology.…”