Magnetocaloric effect above room temperature in the ordered double-perovskite Ba2Fe1+xMo1−xO6

Effect of partial substitution of Cr3+ for Fe3+ on magnetism, magnetocaloric effect and transport properties of Ba2FeMoO6 double perovskites

“…The significant decrease of the saturation magnetic moment with x might be attributed to the increase of the anti-site disorder defects [22,23] or magnetic dilution due to the substitution of Cr for Fe. The values of S for pure compounds are in good agreement of those values reported in literatures [14,19]. It is worth noting that the observed value of the saturation magnetic moment for Ba 2 FeMoO 6 double perovskite lies slightly below the theoretical value of 4 B /f.u.…”

“…Table 1 Unit cell parameter, magnetic, magnetocaloric and transport data of Ba2Fe1−xCrxMoO6 (0 ≤ x ≤ 1). The T C value at x = 0 is similar to that of Ba 2 FeMoO 6 sample reported by Zhong et al [14]. Furthermore, the magnetization decreases gradually with the increasing of small amounts of Cr doping (Fig.…”

“…In order to make a comparison of the maximum entropy change values for these samples with those reported in literatures for several materials considered Table 2. One should be noted that the value of the maximum entropy changes for Ba 2 Fe 1−x Cr x MoO 6 with x = 0 sample above 300 K at 1 T is found to be 25% higher than that for Ba 2 FeMoO 6 sample under a field change of 1 T reported by Zhong et al [14]. However, our value of the maximum entropy change for Ba 2 Fe 1−x Cr x MoO 6 with x = 1 under field change of 1 T is lower than that value reported by Dhahri et al [16] for Ba 2 CrMoO 6 under a field change of 1 T. Furthermore, it is important to see also from Table 2 that the value of S max M obtained in the Ba 2 Fe 1−x Cr x MoO 6 with x = 0 sample is about 64% that of pure Gd, which is thought to be the optimum magnetic refrigerant for use near room temperature.…”

“…Furthermore, several authors have investigated the magnetocaloric effect in ABO 3 type perovskite manganites and found their magnetic entropy change is comparable to that of Gd [28][29][30][31][32]. However, to our knowledge little results have been reported on the MCE of the double perovskite transition oxide [14][15][16]. Here, we study the effect of Cr doping at B-site (Fe) in the polycrystalline Ba 2 Fe 1−x Cr x MoO 6 (0 ≤ x ≤ 1) double perovskite on the magnetocaloric properties.…”

“…For example, in most studied compound, Sr 2 FeMoO 6 , partial or complete substitutions onto the Fe site is a useful method to probe the physics because the magnetic and electronic properties are critically dependent on the exchange splitting of the Fe 2 (t 2g ) and (e g ) orbitals [11]. On the other hand, several authors have investigated the effect of a number of substitutions on B and/or Bsites in the double perovskite on structural, magnetic, transport, magneto-transport, and magnetocaloric properties [11][12][13][14][15][16][17][18]. To our knowledge, no studies have carried on the magnetocaloric effect (MCE) of the Ba 2 Fe 1−x Cr x MoO 6 double perovskite.…”