Mixed valence and metamagnetism in a metal flux grown compound Eu2Pt3Si5

highlights
• A new compound Eu2Pt3Si5 has been synthesized using indium as an inactive metal flux.
• The compound undergoes metamagnetic transition at higher field.
• Eu in this compound resides in a mixed valence state.

A new compound Eu2Pt3Si5 with plate shaped morphology has been grown from excess In flux. The compound crystallizes in the orthorhombic U2Co3Si5 structure type, Ibam space group and the lattice parameters are a=10.007(2) Å, b=11.666(2) Å and c=6.0011(12) Å. The crystal structure of this compound can be conceived as inter-twinned chains of [Pt2Si2] and [PtSi3] tetrahedra connected along [100] direction to give rise to a complex three dimensional [Pt3Si5] network. Temperature dependent magnetic susceptibility data suggests that Eu2Pt3Si5 undergoes a strong antiferromagnetic ordering (TN=19 K) followed by a weak ferromagnetic transition (TC=5.5 K). The effective magnetic moment/Eu obtained from susceptibility data is 6.78 μB accounts mixed valent Eu with almost 85% divalent Eu, which is supported by X-ray absorption near edge spectroscopy. The compound undergoes a metamagnetic transition under applied magnetic field through a probable spin flop mechanism.

Eu2Pt3Si5, a new member in the U2Co3Si5 (Ibam) family undergoes metamagnetic transition at high magnetic field and Eu is in mixed valence state.Figure optionsDownload as PowerPoint slide