High-pressure and high-temperature synthesis of heavy lanthanide sesquisulfides Ln 2S3 (Ln=Yb and Lu)

Highlights: • The phase diagrams of Yb2S3 and Lu2S3 using zeta-phase are provided. • The P-T region of the phase diagrams of Yb2S3 and Lu2S3 using elements was expanded. • Single gamma-phases of Yb2S3 and Lu2S3 were obtained using high-pressure synthesis. • The data of low-temperature physical properties for the compounds are provided. Detailed pressure-temperature phase diagrams of heavy lanthanide sesquisulfides Ln₂S₃ (Ln = Yb and Lu) have been investigated by in-situ x-ray diffraction experiments under high pressure and high temperature using synchrotron radiation and multi-anvil press. Based on the results of the in-situ observation, the single γ-phase (Th₃P₄-type structure, I$\overline{4}$3d) samples of Ln₂S₃ (Ln = Yb and Lu) have been synthesized under high pressure. The physical properties of the compounds were studied by electrical resistivity, specific heat, and magnetic susceptibility measurements between 2 K and 300 K.