The establishment of complexity in solids by kinetically controlled syntheses represents an important concept of functional (nano)materials science. The detailed characterization of them complexity on multiscales calls for a combined approach of complementary analytical methods to determine the nature and stability of the nanostructured materials as well as to find interrelations of structure and function. For the bulk system Ni-Cr-S nanoscale demixing can be obtained after rapid thermal treatment [1]. Atomic scale analyses demonstrate the fully unstrained segregation of a network structure from a matrix material and the non-correlated coexistence of two closely related structure types.
In situ TEM and Synchrotron-based X-ray diffraction (XRD) were applied for studying the chemical and structural inhomogeneity limits. Layered transition metal dichalcogenides (TMDCs) and heterostructures were synthesized via the modulated elemental reactants (MER) approach. In case of few-layer MoSe₂ [2] XRD and TEM determined a complex disordering between adjacent layers, even at the nanometer scale which is interrelated to ultralow cross-plane thermal conductivity. Different La–V–Se heterostructures [3] were analyzed via structural refinement combining TEM imaging and Rietveld analysis. Interestingly, V–Se slabs resemble the structure of V₃Se4 with partially filled van der Waals gaps. The electronic properties of the films are adjustable through layer-sequence design. Cu–Sb–Te layered nanosystems [4, 5] were prepared via Cu diffusion into epitaxial Sb₂Te₃ films. A new Cu₇(Sb₀.₄Te₀.₆)₄ phase with a three-Te-layer unit was identified, structurally different to the bulk phase of Cu₇Te₄. Advanced microscopy revealed a high density of Sb, Te antisite defects and Cu vacancies.
Chemically inhomogeneous nanoparticles (NP) can be produced by laser ablation synthesis in liquids (LAL). For the systems Au-Fe [6] and Au-Co [7] the different components of the NP (e.g., shells, cores, multi-cores) change characteristically in the chemical inhomogeneity during heating and etching experiments. LAL also provides a versatile route to synthesize, e.g., CrMnFeCoNi and CrFeCoNiCu high-entropy alloy (HEA) NP. Structural outcomes depend strongly on laser pulse duration: picosecond pulses yield crystalline NPs, while nanosecond pulses favor metastable amorphous metallic-glass structures. The ability to design amorphous and crystalline structures solely by laser parameters offers a scalable method for tailoring HEA NP functionality. The amorphous phase formation in ns-LAL is attributed to slower solidification and carbon incorporation [8]. The process was further extended to microparticle laser fragmentation in liquid (MP-LFL), confirming scalability [9]. Notably, Cu substitution for Mn stabilizes amorphous phases through Cu-assisted carbon uptake. TEM at identical location (ILTEM) was applied for ignoble and noble metal alloy systems for first etching experiments on the same NP.
References:
[1] Groß, H., et al (2019) J. Mater. Chem.C, 7(48), 15188-15196;
[2] Hadland, E. C., et al. (2019) Nanotechnology, 30(28), 285401;
[3] Gunning, N. S., et al. (2017) Chem. Mater., 29(19), 8292-8298;
[4] Lotnyk, A., et al. (2025) ACS Appl. Nano Material, accepted;
[5] Braun, N., et al. (2025) preprint available at SSRN 5573121;
[6] Kamp, M., et al. (2018) Crystal Growth & Design, 18(9), 5434-5440;
[7] Johny, J., et al. (2021) J. Phys. Chem. C, 125(17), 9534-49;
[8] Stuckert, R., et al. (2025) Beilstein Archives, 2025(1), 8;
[9] Stuckert, R., et al. (2026) Faraday Discussions, accepted.
Lorenz Kienle came to Kiel in 2008 in the context of a Heisenberg professorship funded by the DFG and Kiel University and holds the Chair Synthesis and Real Structure. Through diverse, highly interdisciplinary research projects beyond Materials Science, the study group is active across the university in a wide range of fields, including archaeology, biology, chemistry, electrical engineering, computer science, medicine and physics. Prof. Kienle heads the Center for Transmission Electron Microscopy (TEM). His research focus is on the synthesis of novel bulk and nanomaterials using chemical processes and thin film deposition methods as well as their characterisation using state-of-the-art nanoanalytical methods such as transmission electron microscopy, Synchrotron-based X-ray diffraction and others.
The establishment of complexity in solids by kinetically controlled syntheses represents an important concept of functional (nano)materials science. The detailed characterization of them complexity on multiscales calls for a combined approach of complementary analytical methods to determine the nature and stability of the nanostructured materials as well as to find interrelations of structure and function. For the bulk system Ni-Cr-S nanoscale demixing can be obtained after rapid thermal treatment [1]. Atomic scale analyses demonstrate the fully unstrained segregation of a network structure from a matrix material and the non-correlated coexistence of two closely related structure types.
In situ TEM and Synchrotron-based X-ray diffraction (XRD) were applied for studying the chemical and structural inhomogeneity limits. Layered transition metal dichalcogenides (TMDCs) and heterostructures were synthesized via the modulated elemental reactants (MER) approach. In case of few-layer MoSe₂ [2] XRD and TEM determined a complex disordering between adjacent layers, even at the nanometer scale which is interrelated to ultralow cross-plane thermal conductivity. Different La–V–Se heterostructures [3] were analyzed via structural refinement combining TEM imaging and Rietveld analysis. Interestingly, V–Se slabs resemble the structure of V₃Se4 with partially filled van der Waals gaps. The electronic properties of the films are adjustable through layer-sequence design. Cu–Sb–Te layered nanosystems [4, 5] were prepared via Cu diffusion into epitaxial Sb₂Te₃ films. A new Cu₇(Sb₀.₄Te₀.₆)₄ phase with a three-Te-layer unit was identified, structurally different to the bulk phase of Cu₇Te₄. Advanced microscopy revealed a high density of Sb, Te antisite defects and Cu vacancies.
Chemically inhomogeneous nanoparticles (NP) can be produced by laser ablation synthesis in liquids (LAL). For the systems Au-Fe [6] and Au-Co [7] the different components of the NP (e.g., shells, cores, multi-cores) change characteristically in the chemical inhomogeneity during heating and etching experiments. LAL also provides a versatile route to synthesize, e.g., CrMnFeCoNi and CrFeCoNiCu high-entropy alloy (HEA) NP. Structural outcomes depend strongly on laser pulse duration: picosecond pulses yield crystalline NPs, while nanosecond pulses favor metastable amorphous metallic-glass structures. The ability to design amorphous and crystalline structures solely by laser parameters offers a scalable method for tailoring HEA NP functionality. The amorphous phase formation in ns-LAL is attributed to slower solidification and carbon incorporation [8]. The process was further extended to microparticle laser fragmentation in liquid (MP-LFL), confirming scalability [9]. Notably, Cu substitution for Mn stabilizes amorphous phases through Cu-assisted carbon uptake. TEM at identical location (ILTEM) was applied for ignoble and noble metal alloy systems for first etching experiments on the same NP.
References:
[1] Groß, H., et al (2019) J. Mater. Chem.C, 7(48), 15188-15196;
[2] Hadland, E. C., et al. (2019) Nanotechnology, 30(28), 285401;
[3] Gunning, N. S., et al. (2017) Chem. Mater., 29(19), 8292-8298;
[4] Lotnyk, A., et al. (2025) ACS Appl. Nano Material, accepted;
[5] Braun, N., et al. (2025) preprint available at SSRN 5573121;
[6] Kamp, M., et al. (2018) Crystal Growth & Design, 18(9), 5434-5440;
[7] Johny, J., et al. (2021) J. Phys. Chem. C, 125(17), 9534-49;
[8] Stuckert, R., et al. (2025) Beilstein Archives, 2025(1), 8;
[9] Stuckert, R., et al. (2026) Faraday Discussions, accepted.
Lorenz Kienle came to Kiel in 2008 in the context of a Heisenberg professorship funded by the DFG and Kiel University and holds the Chair Synthesis and Real Structure. Through diverse, highly interdisciplinary research projects beyond Materials Science, the study group is active across the university in a wide range of fields, including archaeology, biology, chemistry, electrical engineering, computer science, medicine and physics. Prof. Kienle heads the Center for Transmission Electron Microscopy (TEM). His research focus is on the synthesis of novel bulk and nanomaterials using chemical processes and thin film deposition methods as well as their characterisation using state-of-the-art nanoanalytical methods such as transmission electron microscopy, Synchrotron-based X-ray diffraction and others.
