Low-temperature large magnetocaloric effect in the antiferromagnetic CeSi compound

Magnetic properties and magnetocaloric effect (MCE) of the CeSi compound are investigated. The compound is determined to be antiferromagnet with the Néel temperature TN = 6.1 K. A metamagnetic transition from antiferromagnetic (AFM) to ferromagnetic (FM) state occurs at 2 K under an applied magnetic field of 4 kOe. Field variation generates a large MCE and no magnetic hysteresis loss is observed. The maximum values of magnetic entropy change (ΔS) are found to be −7.2 J/kg K and −13.7 J/kg K for the field changes of 0-20 kOe and 0-50 kOe, respectively. The large ΔS with no hysteresis loss as well as low price of crude materials make CeSi a competitive candidate for low temperature magnetic refrigerant. In addition, the unusual magnetism in CeSi can be attributed to the appearance of a quartet ground state.