Abrupt Change in Electronic States under Pressure in New Compound EuPt3Al5

We successfully grew single crystals of a new ternary Eu-divalent compound, EuPt3Al5, with an orthorhombic structure (Pnma, #62) using the Bridgman method. EuPt3Al5 orders antiferromagnetically below T-N = 12.4 K. T-N increases monotonically with increasing pressure up to 8.0 GPa, decreases slightly at 8.5 GPa, and suddenly becomes zero above 9.5 GPa. From the results of low-temperature dependences of electrical and residual resistivities, a sudden disappearance of the antiferromagnetic ordering occurs with a dramatic change in the Eu electronic states from the nearly divalent state to the valence fluctuating state at P-c approximate to 9 GPa. EuPt3Al5 is most likely the second material exhibiting an abrupt valence crossover in Eu compounds after EuCu2Ge2.

Automated summary

The research team successfully grew single crystals of a new ternary Eu-divalent compound, EuPt3Al5, and observed its antiferromagnetic ordering. Pressure has a significant influence on the antiferromagnetic ordering of EuPt3Al5, and it suddenly disappears above 9 GPa, accompanied by a dramatic change in the Eu electronic states.