Structural, magnetic, and magnetocaloric properties of chromium doped Gd3Fe5-xCrxO12 garnet compound

Abstract

The detailed structural, magnetic, and cryogenic magneto-caloric properties of chromium-substituted gadolinium iron garnet (Gd3Fe5- xCr xO12) nanocrystalline powders were studied using the facile autocombustion method and a calcination temperature of 1100 °C. The X-ray diffraction pattern showed that all samples were single-phase with cubic Ia3 d symmetry. The temperature and field-dependent magnetization data of Gd3Fe5- xCr xO12 samples revealed a ferrimagnetic ordering at low temperatures. Upon Cr3+ substitution, the Curie temperature reduced by 7% at x = 0.25 from 560 K for x = 0.00 sample. In a field up to 5 T, the maximum magnetic entropy change was observed as Δ S M ∼ 3.8 J K−1 kg−1 for x = 0.00 and −Δ S M ∼ 3.9 J K−1 kg−1 for x = 0.25 sample, while the maximum relative cooling power, RCP, value of 420 J kg−1 was measured for x = 0.25 sample, which is 10% larger than the x = 0.00 (RCP ∼ 380 J kg−1). Therefore, Cr3+ substituted Gd3Fe5- xCr xO12 samples exhibit promising magneto-caloric performance and have potential low-temperature magnetic refrigeration applications.

Magnetocaloric materials for hydrogen liquefaction

“…303 Unfortunately, the few recent attempts to find garnets with higher transition temperatures lead to poor MCE. 305,306…”

Magnetic Memory and the Promising Magnetocaloric Effect of Sn0.6Cr0.1Ge0.3Te Solid Solution Synthesized by Sealed Tube Solid-State Reaction

“…Their findings revealed magnetic entropy changes of 0.5 ( x = 0.01) and 11 J/kg-K ( x = 0.62), indicating that Cr doping induces the MCE. In another study, Sultana et al examined the structural, magnetic, and cryogenic magnetocaloric properties of chromium-substituted gadolinium iron garnet (Gd 3 Fe 5– x Cr x O 12 ) nanocrystalline materials. Their results showed that the maximum magnetic entropy change was observed as −Δ S M ∼ 3.8 J/kg-K for x = 0 and −Δ S M ∼ 3.9 J/kg-K for x = 0.25 samples, further supporting the notion that Cr doping can induce the MCE.…”