Single crystals of EuPtSi3, which crystallize in the BaNiSn3-type crystal structure, have been grown by high temperature solution growth method using molten Sn as the solvent. EuPtSi3 which lacks the inversion symmetry and has only one Eu site in the unit cell is found to be an antiferromagnet with two successive magnetic transitions at TN1 = 17 K and TN2 = 16 K, as inferred from magnetic susceptibility, heat capacity and 151Eu M\"ossbauer measurements. The isothermal magnetization data for H∥ [001] reveal a metamagnetic transition at a critical field Hc = 1 T. The magnetization saturates to a moment value of 6.43 μB/Eu above 5.9 T (9.2 T) for H∥ [001] ([100]), indicating that these fields are spin-flip fields for the divalent Eu moments along the two axes. The origin of this anisotropic behaviour is discussed. A magnetic (H, T) phase diagram has been constructed from the temperature dependence of isothermal magnetization data. The reduced jump in the heat capacity at TN1 indicates a transition to an incommensurate, amplitude modulated antiferromagnetic structure. The shape of the hyperfine field split M\"ossbauer spectrum at TN1 provides additional support for the proposed nature of this magnetic transition.
@article{arxiv.0910.3517,
title = {Magnetic properties of EuPtSi$_3$ single crystals},
author = {Neeraj Kumar and S. K. Dhar and P. Manfrinetti and P. Bonville and A. Thamizhavel},
journal= {arXiv preprint arXiv:0910.3517},
year = {2011}
}