@misc{ZeugnerKaiserSchmidtetal., author = {Zeugner, Alexander and Kaiser, Martin and Schmidt, Peer and Menshchikova, Tatiana V. and Rusinov, Igor P. and Markelov, Anton V. and Van den Broek, Wouter and Chulkov, Evgueni V. and Doert, Thomas and Ruck, Michael and Isaeva, Anna}, title = {Modular Design with 2D Topological-Insulator Building Blocks: Optimized Synthesis and Crystal Growth and Crystal and Electronic Structures of BiₓTeI (x = 2, 3)}, series = {Chemistry of Materials}, volume = {29}, journal = {Chemistry of Materials}, number = {3}, issn = {0897-4756}, doi = {10.1021/acs.chemmater.6b05038}, pages = {1321 -- 1337}, abstract = {Structural engineering of topological bulk materials is systematically explored with regard to the incorporation of the buckled bismuth layer [Bi₂], which is a 2D topological insulator per se, into the layered BiTeI host structure. The previously known bismuth telluride iodides, BiTeI and Bi₂TeI, offer physical properties relevant for spintronics. Herewith a new cousin, Bi₃TeI (sp.gr. R3m, a = 440.12(2) pm, c = 3223.1(2) pm), joins the ranks and expands this structural family. Bi₃TeI = [Bi₂][BiTeI] represents a stack with strictly alternating building blocks. Conditions for reproducible synthesis and crystal-growth of Bi₂TeI and Bi₃TeI are ascertained, thus yielding platelet-like crystals on the millimeter size scale and enabling direct measurements. The crystal structures of Bi₂TeI and Bi₃TeI are examined by X-ray diffraction and electron microscopy. DFT calculations predict metallic properties of Bi₃TeI and an unconventional surface state residing on various surface terminations. This state emerges as a result of complex hybridization of atomic states due to their strong intermixing. Our study does not support the existence of new stacking variants BiₓTeI with x > 3; instead, it indicates a possible homogeneity range of Bi₃TeI. The series BiTeI-Bi₂TeI-Bi₃TeI illustrates the influence of structural modifications on topological properties.}, language = {en} } @misc{KniesKaiserLeAnhetal., author = {Knies, Maximilian and Kaiser, Martin and L{\^e} Anh, Mai and Efimova, Anastasia and Doert, Thomas and Ruck, Michael}, title = {Low-Temperature Ordering in the Cluster Compound (Bi₈)Tl[AlCl₄]₃}, series = {Inorganics}, volume = {7}, journal = {Inorganics}, number = {4}, doi = {10.3390/inorganics7040045}, pages = {1 -- 9}, abstract = {The reaction of Bi, BiCl₃, and TlCl in the ionic liquid [BMIm]Cl·4AlCl₃ (BMIm = 1-n-butyl-3-methylimidazolium) at 180 °C yielded air-sensitive black crystals of (Bi₈)Tl[AlCl₄]₃. X-ray diffraction on single crystals at room temperature revealed a structure containing [Tl(AlCl₄)₃]∞12- strands separated by isolated Bi₈²⁺ square antiprisms. The thallium(I) ion is coordinated by twelve Cl⁻ ions of six [AlCl₄]⁻ groups, resulting in a chain of face-sharing [TlCl₁₂]¹¹⁻ icosahedra. The Bi₈²⁺ polycation is disordered, simulating a threefold axis through its center and overall hexagonal symmetry (space group P6₃/m). Slowly cooling the crystals to 170 K resulted in increased order in the Bi₈ cluster orientations. An ordered structure model in a supercell with a' = 2a, b' = 2b, c' = 3c and the space group P6₅ was refined. The structure resembles a hexagonal perovskite, with complex groups in place of simple ions.}, language = {en} } @misc{TolksdorfKaiserPetretal., author = {Tolksdorf, Johann Friedrich and Kaiser, Knut and Petr, Libor and Herbig, Christoph and Koč{\´a}r, Petr and Heinrich, Susann and Wilke, Franziska D.H. and Theuerkauf, Martin and F{\"u}lling, Alexander and Schubert, Matthias and Schr{\"o}der, Frank and Křiv{\´a}nek, Roman and Schulz, Lars and Bonhage, Alexander and Hemker, Christiane}, title = {Past human impact in a mountain forest: geoarchaeology of a medieval glass production and charcoal hearth site in the Erzgebirge, Germany}, series = {Regional Environmental Change}, volume = {20}, journal = {Regional Environmental Change}, number = {3}, issn = {1436-378X}, doi = {10.1007/s10113-020-01638-1}, pages = {20}, language = {en} }