Rational synthesis of novel low-dimensional materials by tuning of the Fermi level via chemical doping

• Applicant: Mihai Ionut Sturza, Ph.D.
• Subject Area: Solid State and Surface Chemistry, Material Synthesis
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 332171392

• Final Report Year: 2022

Final Report Abstract

This research program has been focused on the role of synthesis in creating interesting electronic properties emerging from a competition between different electronic states or suppression of the electronic order (a charge, orbital or spin). Our multi-faceted strategy connected solid-state synthesis with state-of-the-art structural and electronic probes. In accordance with the aims and working plan of the proposals we have carried out extensive experimental investigations of novel low-dimensional materials. The following classes of materials have been explored to reach the scientific goals of the project: (i) Intermetallic pnicogen compounds with square lattices: synthesis and crystal growth using different metal flux (Sn, Sb, Bi, In flux) of various layered compounds from the REMX3 system (RE=La, Pr, Nd, Sm; M=Fe, Co, Ni, Cr ,V ,Pd; X=Sb, Bi, Ge) system have been investigated. New ternary compounds have been discovered (La6Pd2+xSb15 (x = 0.28), Nd4Fe3Ge10, NdNiBi2), but also in most of the growth attempts just crystals of binary compounds were observed. (ii) Chalcogenides with low-dimensional structure. The follow compounds have been studied: CuFeTe2 semiconductor, FeTe1-xSex (x=0.45), LaFeAsO(1111) – Iron Based Superconductor (IBS) and quasi-Two-Dimensional (2D) chalcogenides - KCu3−xSe2, quasi-2D magnets (Fe1−xNix)2P2S6 with xNi = 0, 0.3, 0.5, 0.7, 0.9, and 1. The strength of our program was our deep knowledge and intuition of how lowdimensional architectures arrange in complex solids and develop with composition, along with the novel synthetic methodologies we have developed to discover and characterize new compounds.

Publications

• "Copper Vacancies and Heavy Holes in the Two-Dimensional Semiconductor KCu3–xSe2". Chem. Mater. 29, 14, 6114 – 6121 (2017)
  A. J.- E. Rettie, M. Sturza, C. D. Malliakas, A. S. Botana, M. R. Norman, D. Y. Chung, M.G. Kanatzidis
  
• "Solid state single crystal growth of three-dimensional faceted LaFeAsO crystals". J. Cryst. Growth 483, 9-15 (2018)
  R. Kappenberger, S. Aswartham, F. Scaravaggi, C. Blum, M. Sturza, A.U.B. Wolter-Giraud, B. Büchner, S. Wurmehl
  
• "Engineering Kitaev exchange in stacked iridate layers: impact of inter-layer species on in-plane magnetism". Chem. Sci. 10, 1866-1872 (2019)
  R. Yadav, M. S. Eldeeb, R. Ray, S. Aswartham, M. I. Sturza, S. Nishimoto, J. van den Brink and L. Hozoi
  
• "La6Pd2+xSb15 (x = 0.28): A Rare-earth Palladium Intermetallic Compound with Extended Pnictogen Ribbons". Solid State Chem. 291, 121578 (2020)
  M. I. Sturza, M. L. Amigó, J. I. Facio, F. Caglieris, S. Aswartham, S. Seiro, C. Hess, J. van den Brink, S. Wurmehl, B. Büchner
  
• "Magnetic interactions in the tripod-kagome antiferromagnet Mg2Gd3Sb3O14". Phys. Rev. B 102 (21), 214414 (2020)
  C. Wellm, J. Zeisner, A. Alfonsov, M.-I. Sturza, G. Bastien, S. Gaß, S. Wurmehl, A. U. B. Wolter, B. Büchner, V. Kataev
  
• "Quasi-2D magnetic correlations in Ni2P2S6 probed by 31P NMR". Phys. Rev. B 102 (6), 064429 (2020)
  A. P. Dioguardi, S. Selter, S. Aswartham, M.-I. Sturza, R. Murugesan, M. S. Eldeeb, L. Hozoi, B. Büchner, H.-J. Grafe
  
• "Strongly correlated superconductor with polytypic 3D Dirac points". npj Quantum Mater. 5, 67 (2020)
  S. Borisenko, V. Bezguba, A. Fedorov, Y. Kushnirenko, V. Voroshnin, M. Sturza, S. Aswartham, A. Yaresko
  
• “Discovery, Crystal Growth, and Characterization of Garnet Eu2PbSb2Zn3O12“. Eur. J. Inorg. Chem. 26, 2512–2520 (2020)
  R. Morrow M. I. Sturza, R. Ray, C. Himcinschi, J. Kern, P. Schlender, M. Richter , S. Wurmehl, B. Büchner
  
• "Crystal Growth and Anisotropic Magnetic Properties of Quasi-2D (Fe1−xNix)2P2S6". Phys. Rev. Materials 5, 073401 (2021)
  S. Selter, Y. Shemerliuk, M.-I. Sturza, A. U. B. Wolter, B. Büchner, S. Aswartham
  
• “Bulk and Single Crystal Growth Progress of Iron-Based Superconductors (FBS): 1111 and 1144”. Crystals 12, 20 (2022)
  S. J. Singh and M. I. Sturza