Magnetic Properties and Magnetocaloric Effect οf R1-xR'xMn2Ge2 Compounds

M. Duraja and A. Szytułab a Institute of Physics, Technical University of Cracow, Podchorążych 1, 30-084 Kraków, Poland b M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, 30-059 Kraków, Poland

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The magnetic and magnetocaloric properties of Sm1-xGdxMn2Ge2 compounds with 0 ≤ x ≤ 0.10 have been studied. SmMn2Ge2 is antiferromagnetic below the Néel temperature TN ( ≈ 400 K). Further cooling leeds to canted ferromagnetic phase below TC = 341 K. With decreasing temperature, two metamagnetic phase transitions are observed: F2-AF1 at T2 = 153 K and AF1-F1 at T1 = 106 K. The maximum values of magnetic entropy change | Δ Sm | are found to be 1.5 J K-1 kg-1 at T1 and 2.0 J K-1 kg-1 at T2 in SmMn2Ge2. The MCE is found to increase with Gd concentration, | Δ Sm(T1) | = 3.3 J K-1 kg-1, while | Δ Sm(T2)| is slightly enhanced for x = 0.1. The magnetocaloric effect is found to be positive at T1 and negative at T2.

DOI: 10.12693/APhysPolA.117.603 PACS numbers: 75.30.Kz, 75.30.Sg