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The solid solution LnSbxTe2−x−δ (Ln = lanthanide) is a family of square-net topological semimetals that exhibit tunable charge density wave (CDW) distortions and band filling dependent on x, offering broad opportunities to examine the interplay of topological electronic states, CDW, and magnetism. While several Ln series have been characterized, gaps in the literature remain, inviting a systematic survey of the remaining composition space that is synthetically accessible. We present our efforts to synthesize LnSbxTe2−x−δ across the remaining lanthanides via chemical vapor transport. Compiling our results with the reported literature, we generate a stability phase diagram across the ranges of Ln and x. We find a stability boundary for intermediate x beyond Tb, while x = 1 and x = 0 can be isolated up to Ho and Dy, respectively. SEM and XRD analyses of unsuccessful reactions indicated the formation of several stable binary phases. The presence of structurally related LnTe3 in samples suggests that stability is limited by the size of Ln, due to increasing compressive strain along the layer stacking axis with decreasing size. Finally, we demonstrate that late Ln can be stabilized in LnSbxTe2−x−δ via substitution into larger Ln members, synthesizing La1−yHoySbxTe2−x−δ as a proof of concept.
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Optical-Pump Terahertz-Probe Spectroscopy of the Topological Crystalline Insulator Pb 1–x Sn x Se through the Topological Phase Transition
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Abstract This study presents a thorough analysis of the electronic structures of the TaPxAs1−xseries of compounds, which are of significant interest due to their potential as topological materials. Using a combination of first principles and Wannier‐based tight‐binding methods, this study investigates both the bulk and surface electronic structures of the compounds for varying compositions (x = 0, 0.25, 0.50, 0.75, 1), with a focus on their topological properties. By using chirality analysis, (111) surface electronic structure analysis, and surface Fermi arcs analysis, it is established that the TaPxAs1−xcompounds exhibit topologically nontrivial behavior, characterized as Weyl semimetals (WSMs). The effect of spin–orbit coupling (SOC) on the topological properties of the compounds is further studied. In the absence of SOC, the compounds exhibit linearly dispersive fourfold degenerate points in the first Brillouin zone (FBZ) resembling Dirac semimetals. However, the introduction of SOC induces a phase transition to WSM states, with the number and position of Weyl points (WPs) varying depending on the composition of the alloy. For example, TaP has 12 WPs in the FBZ. The findings provide novel insights into the electronic properties of TaPxAs1−xcompounds and their potential implications for the development of topological materials for various technological applications.more » « less
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1021/acsphotonics.1c01717
