Anisotropic magnetic properties of EuAl2Si2

Arvind Maurya (1) , Ruta Kulkarni (1) , A Thamizhavel (1) , Pierre Bonville (2, 3) , S K Dhar (1)

1 CMPMS - Department of Condensed Matter Physics and Materials Science [TIFR]
2 LNO - Laboratoire Nano-Magnétisme et Oxydes
3 SPEC - UMR3680 - Service de physique de l'état condensé

EuAl2Si2 is known to crystallize in the CaAl2Si2-type trigonal structure. We have grown single crystals of EuAl2Si2 by flux method, using Al-Si eutectic (87.8% Al) as self-flux, and investigated their anisotropic magnetic properties by means of magnetization, electrical resistivity and heat capacity in zero and applied magnetic fields, and 151Eu Mössbauer spectroscopy. Magnetic susceptibility data show an antiferromagnetic transition at TN = 33.3 K in agreement with the previously reported value on polycrystalline sample. The isothermal magnetization at 2 K measured along and perpendicular to the c-axis shows anisotropic behaviour, which is rather unexpected as Eu2+ is an S-state ion. The spin flip fields along the two directions are 2.8 and 4.8 T, respectively, while two closely spaced spin-flop transitions in the ab-plane are observed near 1.4 and 1.6 T. The electrical resistivity shows an upturn between TN and 60 K as the temperature is lowered below ~ 60 K, suggesting the presence of antiferromagnetic correlations in the paramagnetic state. Magnetoresistivity at 2 K in 14 T is nearly 1070 % for H // [0001]. The results of heat capacity and 151Eu Mössbauer spectroscopy are in conformity with a bulk transition at 33.3 K.

Domaines: Physique [physics]

Arvind Maurya, Ruta Kulkarni, A Thamizhavel, Pierre Bonville, S K Dhar. Anisotropic magnetic properties of EuAl2Si2. Journal of Physics: Conference Series, 2015, 592, ⟨10.1088/1742-6596/592/1/012045⟩. ⟨cea-01366333⟩