Humboldt-Universität zu Berlin - Faculty of Mathematics and Natural Sciences - Novel Materials

Ultra-thin layers

ultrathin round.pngStudied are the surface- and interface effects in spin and charge transport in material systems of metals, semiconductors, superconductors and the novel materials class of topological insulators.

Investigated are thin epitaxial layers prepared by exfoliation technique and atomically-thin novel material layer systems, such as ferecrystals. Investigations of the transport properties of topological insulators, semiconductor/superconductor hybrids or metal/semiconductor hybrids are performed with respect to the influence of electrical fields, low- and high-magnetic fields and temperature.

We are particularly interested in topological surface states, phase transitions to emergent phenomena (superconductivity, charge-density waves) and proximity effects at hybrid interfaces. Materials presently under investigation are ultra-thin layers based on novel oxides (Ga2O3, SrTiO3, CaVO3), topological insulators (Bi2Se3,Bi2Te3, Bi-Se-Te) and ferecrystals (NbSe2, SnSe).

Novel Materials Group
Prof. Dr. Saskia F. Fischer  email

Associated researchers
Dr. Olivio Chiatti  email
Dr. Rüdiger Mitdank  email
MSc. Linus Grote  email
MSc. Mahni Müller  email
BSc. María Sofia Espinosa Gonzalez  email

Further research topics

Nanostructures | Quantum systems | Novel semiconductor materials


Selected Publications


Superconductive coupling in tailored ([SnSe]1+δ)m(NbSe2)1 multilayers
M. Trahms, C. Grosse, M. B. Alemayehu, O. K. Hite, O. Chiatti, A. Mogilatenko, D. C. Johnson, and S. F. Fischer
Supercond. Sci. Technol. 31, 065006 (2018).
Short abstract

High-temperature quantum oscillations of the Hall resistance in bulk Bi2Se3
M. Busch, O. Chiatti, S. Pezzini, S. Wiedmann, J. Sánchez-Barriga, O. Rader, L. V. Yashina, and S. F. Fischer
Sci. Rep. 8, 485 (2018).
Short abstract

Superconducting Tin Selenide/Niobium Diselenide Ferecrystals
C. Grosse, M. B. Alemayehu, A. Mogilatenko, O. Chiatti, D. C. Johnson, and
S. F. Fischer
Cryst. Res. Technol. 52, 1700126 (2017).
Short abstract

Superconducting ferecrystals: turbostratically disordered atomic-scale layered (PbSe)1.14(NbSe2)n thin films
C. Grosse, M. B. Alemayehu, M. Falmbigl, A. Mogilatenko, O. Chiatti, D. C. Johnson, and S. F. Fischer
Sci. Rep. 6, 33457 (2016).
Short abstract

2D layered transport properties from topological insulator Bi2Se3 single crystals and micro flakes
O. Chiatti, C. Riha, D. Lawrenz, M. Busch, S. Dusari, J. Sánchez-Barriga, A. Mogilatenko, L. V. Yashina, S. Valencia, A. A. Ünal, O. Rader, and S. F. Fischer
Sci. Rep. 6, 27483 (2016).
Short abstract

Suppressing a Charge Density Wave by Changing Dimensionality in the Ferecrystalline Compounds ([SnSe]1.15)1(VSe2)n with n = 1, 2, 3, 4
M. Falmbigl, A. Fiedler, R. E. Atkins, S. F. Fischer, and D. C. Johnson
Nano Lett. 15 (2), 943–948 (2015).
DOI: 10.1021/nl503708j
Short abstract

Structural and Electrical Properties of ([SnSe]1+δ)m(NbSe2)1 Compounds: Single NbSe2 layers separated by increasing thickness of SnSe
M. B. Alemayehu, M. Falmbigl, K. Ta, C. Grosse, R. D. Westover, S. R. Bauers, S. F. Fischer, and D. C. Johnson
Chem. Mater. 27, 867-875 (2015).
DOI: 10.1021/cm5039864
Short abstract

Synthesis of Inorganic Structural Isomers By Diffusion-Constrained Self-Assembly of Designed Precursors: A Novel Type of Isomerism
M. Esters, M. B. Alemayehu, Z. Jones, N. T. Nguyen, M. D. Anderson, C. Grosse, S. F. Fischer, and D. C. Johnson
Angew. Chem. Int. Ed. 54, 1130-1134 (2015).
DOI: 10.1002/anie.201409714
Short abstract
Hot paper

Structural and electrical properties of a new ([SnSe]1.16)1(NbSe2)1 polytype
M. B. Alemayehu, M. Falmbigl, C. Grosse, K. Ta, S. F. Fischer, and D. C. Johnson
J. Alloys Compd. 619, 861-868 (2015).
DOI: 10.1016/j.jallcom.2014.09.084
Short abstract

Synthesis and Systematic Trends in Structure and Electrical Properties of [(SnSe)1.15]m(VSe2)1, m = 1, 2, 3, and 4
R. Atkins, M. Dolgos, A. Fiedler, C. Grosse, S. F. Fischer, S. P. Rudin, and D. C. Johnson
Chem. Mater. 26 (9), 2862–2872 (2014).
DOI: 10.1021/cm5004774
Short abstract

Temperature-dependent electrical characterization of exfoliated ß-Ga2O3 micro flakes
R. Mitdank, S. Dusari, C. Bülow, M. Albrecht, Z. Galazka, and S. F. Fischer
Phys. Status Solidi A 211, No. 3, 543-549 (2014).
DOI: 10.1002/pssa.201330671
Short abstract

Synthesis, structure and electrical properties of a new tin vanadium selenide
R. Atkins, S. Disch, Z. Jones, I. Haeusler, C. Grosse, S. F. Fischer, W. Neumann, P. Zschack, and D. C. Johnson
J. Solid State Chem. 202, 128-133 (2013).
DOI: 10.1016/j.jssc.2013.03.008

Coherent spin dynamics in Permalloy-GaAs hybrids at room-temperature
P. E. Hohage, J. Nannen, S. Halm and G. Bacher, M. Wahle, S. F. Fischer, U. Kunze D. Reuter, and A. D. Wieck
Appl. Phys. Lett. 92, 241920 (2008).
DOI: 10.1063/1.2943279

Structural, chemical, and magnetic characterization of Fe films grown on InAs(100)
L. Ruppel, G. Witte, C. Wöll, T. Last, S. F. Fischer, and U. Kunze
Phys. Rev. B
66, 245307-1-8 (2002).
DOI: 10.1103/PhysRevB.66.245307

Critical magnetic properties of polycrystalline Cr75Fe25 and Cr70Fe30 alloys
S. F. Fischer, S. N. Kaul, and H. Kronmüller
Phys. Rev. B 65, 064443-(1-12) (2002).
DOI: 10.1103/PhysRevB.65.064443

Optimization of magnetostriction, coercive field and magnetic transition temperature in nanocrystalline TbDyFe+Zr/Nb Multilayers
S. F. Fischer, M. Kelsch, and H. Kronmüller
J. Magn. Magn. Mat. 195, 545-554 (1999).
DOI: 10.1016/S0304-8853(99)00321-2