Magnetism in DyFe2Si2-a single-crystal study

Results of magnetization (M), AC-susceptibility (χAC), specific heat (C) and electrical-resistivity (ρ) measurements on DyFe2Si2 single crystals are reported and analyzed in conjunction with first-principles electronic-structure calculations. Clear anomalies in the χAC(T), C(T) and ρ(T) dependences indicate a magnetic-phase transition (paramagnetic ↔ antiferromagnetic) at 3.8 K. Magnetic and specific-heat data obtained in magnetic fields (B) manifest uniaxial magnetocrystalline anisotropy with the easy magnetization direction along the c-axis of the tetragonal structure. These findings together with the metamagnetic transition observed on the M(B) curve measured at 2 K and the evolution of the specific-heat anomaly at 3.8 K in a magnetic field applied along the c-axis corroborate a scenario for the physics of DyFe2Si2 in terms of antiferromagnetism with Néel temperature TN=3.8K. The first-principles electronic-structure calculations confirm the absence of an ordered Fe moment, which is in agreement with previously reported experimental findings. The magnetization isotherms and the temperature dependences of the specific heat and paramagnetic susceptibility (M/B) in the paramagnetic state were analyzed taking into account the crystal-field interaction. The experimentally determined crystal-field parameters are compared with the results of first-principles crystal-field calculations.