Synthesis and Crystal Growth Research Team

Intermetallic Magnetic Materials Group

Head: Dr. S. Wurmehl

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Crystal Growth Group

Head: Dr. A. Maljuk

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Intermetallic Magnetic Materials Group

We aim to understand the relation between structure and properties of selected functional materials. For that, we work on developing synthesis and crystal growth routes, on chemical and structural characterization, and on investigating the physical properties of such materials. Relevant materials may comprise but are not limited to intermetallics, and pnictides. Properties of interest include high spin polarization, first order phase transitions, magnetic anisotropy, unconventional superconductivity, frustrated magnetism, strong spin-orbit coupling and nontrivial topology. Our pool of facilities includes different types of furnaces working in various atmospheres, thermal analysis, powder and Laue backscattering x-ray diffraction. For a complete list of our facilities, see here. We also use Nuclear Magnetic Resonance (55Mn and  59Co NMR) to study the local crystallographic, magnetic and electronic structure of ferromagnets in in bulk, thin film and nano-size form.

recent highlights:

Extraction of Dzyaloshinskii-Moriya interaction from propagating spin waves

Lucassen et al., Phys. Rev. B 101, 064432 (2020)

The interfacial Dzyaloshinskii-Moriya interaction (iDMI) is of great interest in thin-film magnetism because of its ability to stabilize chiral spin textures. Here, we utilize all-electrical propagating spin-wave spectroscopy to disentangle multiple contributions to spin wave frequency nonreciprocity to determine the iDMI by investigating nonreciprocities across a wide range of magnetic layer thicknesses (from 4 to 26 nm) in Pt/Co/Ir, Pt/Co/Pt, and Ir/Co/Pt stacks. We find the expected sign change in the iDMI when inverting the stack order and a negligible iDMI for the symmetric Pt/Co/Pt. We additionally extract a difference in surface anisotropies and find a large contribution due to the formation of different crystalline phases of the Co, which is corroborated using nuclear magnetic resonance and high-resolution transmission-electron-microscopy measurements. These insights will open up avenues to investigate, quantify, and disentangle the fundamental mechanisms governing the iDMI, and pave a way toward engineered large spin-wave nonreciprocities for magnonic applications.

Evolution of Structure and Electronic Correlations in a Series of BaT2As2 (T = Cr–Cu) Single Crystals

S. Selter, et al., Inorg. Chem. 59, 16913 (2020)

We present a systematic study of the evolution of structural parameters and electronic correlations as a function of 3d band filling in a single crystal series of BaT2As2 (T = Cr–Cu). Our study finds a strong interplay between crystal structure, bonding behavior, band filling, and electronic properties.

Flux growth of Srn+1IrnO3n+1 (n=1, 2, infinity) crystals

K. Manna, et al., J. Cryst. Growth 540, 125657 (2020)

Single crystals of iridates are usually grown by a flux method well above the boiling point of the SrCl2 solvent, hence, under non-equilibrium growth conditions. Here, we report the growth of Sr2IrO4, Sr3Ir2O7 and SrIrO3 single crystals in a reproducible way by using anhydrous SrCl2 flux well below its boiling point. Reducing the soak temperature below the solvent boiling point not only provides more stable and controllable growth conditions in contrast to previously reported growth protocols, but also extends considerably the lifetime of expensive platinum crucibles and reduces the corrosion of heating and thermoelements of standard furnaces, thereby reducing growth costs.

La6Pd2+xSb15 (x = 0.28): A Rare-earth Palladium Intermetallic Compound with Extended Pnictogen Ribbons

M. I. Sturza, et al., J. Solid State Chem. 291, 121578 (2020)

A new intermetallic ternary compound La6Pd2.28Sb15 was synthesized which crystallizes in the orthorhombic space group. The crystal structure contains a three-dimensional framework of Sb squares and ribbons that extend along the a axis, including complex Sb–Sb bonding. La6Pd2.28Sb15 is diamagnetic and metallic.

Structure-property relationship of Co2MnSi thin films in response to He+-irradiation

F. Hammerath, et al., Scientific reports 9, 2766 (2019)

The structure-property relationship of Co2MnSi Heusler thin films upon the irradiation with He+ ions were studied using nuclear magnetic resonance (NMR) and transmission electron microscopy (TEM), and associated with the corresponding changes of the magnetic behavior.

Magnetic and magnetocaloric properties of the Co2-xMnxB system by experiment and density functional theory

S. Ener, et al. Acta Mater. 165, 270 (2019)

We report on the synthesis of a series of Co2-xMnxB alloys and the investigation of their properties. Measurements of both, macroscopic and local magnetic properties, reveal an anomalous behavior as a function of manganese concentration.The good agreement between the advanced characterization and theory gives a deeper understanding of the Co2-xMnxB material system which can in the future be extended to other systems. Specifically, we find a complex magnetic coupling behavior between Mn atoms, which significantly affects the corresponding exchange interactions.

Group Leader/Head of Department: Dr. Sabine Wurmehl

Room D2E.13     Phone: +49 351 4659 519       Email



Felix Anger

Patrizia Fritsch

Vakula Hlushko

Dr. Andrii Kanak

Gloria Kirste

Robin Kramer

Dr. Wolfgang Löser

Dr. Sabine Wurmehl, see personal wepbpage


Christian Blum

Chika Schlage

Rowena Wachtel

Crystal Growth Group

We grow and characterize single crystals of oxides, sulfides and intermetallic materials exhibiting a variety of properties such as unconventional superconductivity, complex magnetism or ionic conduction.  We use the crucible-free floating zone technique based on optical heating  (including the operation of the  150 bars high-pressure image furnace), the Bridgman and the flux methods. Embedded within this group is the complex magnetic oxides junior research group led by Dr. R. Morrow specializing in double perovskites.

Leader of the Crystal Growth group:                  Dr. Andrey Maljuk 

e-mail:                     phone:  +49 351 4659 633


Leader of the Double Perovskite group:           Dr. Ryan C. Morrow

e-mail:                 phone:  +49 351 4659 228






Olesia Voloshyna        Post-doc          crystal growth                +49 351 4659 801
Anastasiia Smerechuk        PhD student          double perovskite 
Tamara Holub        PhD student          double perovskite 
Robert Kluge       Technician                          +49 351 4659 539


Laser-assisted floating zone growth of BaFe2S3 large-sized ferromagnetic- impurity-free single crystals,  M.L.Amigó, A.Maljuk, K.Manna, Q.Stahl, C.Felser, C.Hess, A.U.B.Wolter, J.Geck, S.Seiro, B.Büchner, Crystals 11, 758 (2021).

TSFZ growth of Nd-substituted LSCO superconducting crystals, O.Voloshyna, K.Karmakar, A.Maljuk, V.V.Romaka, C.G.F. Blum, S.Seiro, B.Büchner, J.Crystal Growth 562, 126082 (2021)

Flux growth of Srn+1IrnO3n+1 (n = 1, 2, ∞), K. Manna, G. Aslan-Cansever, A. Maljuk, S. Wurmehl, S. Seiro, and B. Büchner, J. Crystal Growth 540, 125657 (2020)

Charge transfer energy in iridates: a hard x-ray photoelectron spectroscopy study, D. Takegami, D. Kasinathan, K. K. Wolff, S. G. Altendorf, C.-F. Chang, K. Hoefer, A. Meléndez-Sans, Y. Utsumi, F. Meneghin, T. D. Ha, C.-H. Yen, K. Chen, C.-Y Kuo, Y. F. Liao, K.-D. Tsuei, R. Morrow, S. Wurmehl, B Büchner, B. E. Prasad, M. Jansen, A. C. Komarek, P. Hansmann, L. H. Tjeng, Phys. Rev. B 102, 045119 (2020).

Discovery, Crystal Growth, and Characterization of Garnet Eu2PbSb2Zn3O12, R. Morrow, M. I. Sturza, R. Ray, C. Himcinschi, J. Kern, P. Schlender, S. Wurmehl, B. Büchner, Eur. J. Inorg. Chem. 26, 2512-2520 (2020).

Complex magnetic properties in the mixed 4f−5d double perovskite iridates X2ZnIrO6 (X = Nd, Sm, Eu, Gd), M. Vogl, R. Morrow, A. A. Aczel, R. Beltran Rodriguez, A. U. B. Wolter, S. Wurmehl, S. Aswartham, B. Büchner, Phys. Rev. Materials 4, 054413 (2020).

Laser-diode-heated floating-zone crystal growth of ErVO3, P. Telang, A. Maljuk, D. Rout, R. Hu, M. Skoulatos, K. Karmakar, S. Seiro, B. Roessli, U. Stuhr, B. Büchner, S.-W. Cheong and S. Sing, J. Crystal Growth 507, 406 (2019)

Bichalcogenide Model Systems for Magnetic Chains with Variable Spin Sizes and Optional Crystallographic InversionSymmetry, M. Valldor, R. Morrow, Inorg. Chem. 58 (18), 11978-11982 (2019). [Invited forum paper]

Growth of LiCoO2 single crystals by the TSFZ method,  S.Nakamura, A.Maljuk, Y.Maruyama, M. Nagao, S.Watauchi, T. Hayashi, Y.Anzai, Y.Furukawa, C.D. Ling, G.Deng, M.Avdeev, B.Büchner, I.Tanaka, Crystal Growth and Design 19,  415 (2019)