Emergence of 1/3 magnetization plateau and successive magnetic transitions in Zintl phase Eu_{3}InAs_{3}

Single crystals of Eu_{3}InAs_{3} have been successfully synthesized by indium flux reactions. Eu_{3}InAs_{3} crystallizes in the Ca_{3}AlAs_{3}-type structure with an orthorhombic space-group Pnma. Theoretical calculations indicate that Eu_{3}InAs_{3} is a semiconductor with a direct band gap of 0.3 eV. Eu_{3}InAs_{3} has large negative Seebeck coefficients in the range of 300–450 μV/K at room temperature. Eu_{3}InAs_{3} displays two antiferromagnetic transitions (T_{N1}=13 and T_{N2}=10 K) for both H∥b and H⊥b which can be suppressed by magnetic fields. At 2 K, field-induced ferromagnetic states are reached for both H∥b and H⊥b. Particularly, the H∥b magnetization curves show a plateau at 1/3 of the saturated magnetization and an anomaly at 2/3 of the saturated magnetization. Eu_{3}InAs_{3} is a Zintl phase material showing a 1/3 magnetization plateau here.