Synthesis, sintering, specific heat and magnetism of Eu3S4 by low-temperature CS2-gas sulfurization of Eu2O3 nanospheres

Single-phase Eu₃S₄ was obtained via CS₂ gas sulfurization of Eu₂O₃ nanospheres at 773 K for longer than 0.5 h. The primary particle size of Eu₃S₄ became larger than that of Eu₂O₃ during the sulfurization process. Pure synthetic Eu₃S₄ powders were unstable and transformed to EuS at 873 K under vacuum. Eu₃S₄ compacts were sintered in temperature range of 773 K to 1173 K and they transformed to EuS at 1473 K during spark plasma sintering. Specific heat of sintered Eu₃S₄ did not show an anomalous behavior in the range of 2 K to 50 K. The magnetic susceptibility of polycrystalline Eu₃S₄ followed a Curie-Weiss law from 2 K to 300 K. Magnetization of polycrystalline Eu₃S₄ was larger than that of single crystal Eu₃S₄ when the magnetic field was less than 3.5 kOe.