A05: Designing 4f-3d permanent magnets by tailoring crystal fields

In this subproject Ce-based 4f-3d permanent magnetic materials will be designed using the systematic investigations of thermodynamic phase diagrams and accurate evaluations of the intrinsic magnetic properties for the constitute phases. These parameterized intrinsic magnetic properties will be used in micromagnetic simulations in other HoMMAGE subprojects. The objective of the subproject is to obtain accurate electronic structure based on the state-of-the-art density functional theory combined with the dynamical mean field theory (DFT+DMFT) methods. This should identify the local structural motifs which can be engineered to develop next generation permanent magnets.

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B13: Machine learning assisted hysteresis design

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T03: Adaptives Design von Ni-Mn-Ga-X Heusler-Legierungen für die Anwendung als magnetische Formgedächtnislegierung im Hochtemperaturbereich

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Interplay between magnetism and crystalline environments in Fe-based intermetallic compounds

This subproject C02 addresses the fundamental aspects of end-temperature magnetism and its interplay with the other degrees of freedom in Fe-based intermetallic systems. It is based on density functional theory and dynamic mean-field theory methods combined with accurate atomistic simulations. The objective is to develop effective descriptors to map between the crystal structures and the magnetic properties, to modify the magnetism and thus the physical properties via substitutional and interstitial alloys, and to evaluate the thermodynamic properties upon phase transformations for such materials at both the bulk and nanoparticle boundaries.

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More information on the iron upgraded ! project can be found here.

A01: Fermi level engineering of doped perovskites: From the dilute limit to phase formation

This subproject studies the influence of the Fermi energy on the charge state and lattice relaxation of dopants, impurities and defect complexes including their kinetic behaviour. With the accurate prediction of defect formation energies and transition levels, the interplay of intrinsic and extrinsic defects are being researched. The project focuses on the transition metal (TM) doping, where the transition metal ions can have several valence states due to the interplay of competing interactions. A formalism for describing the transition from the dilute limit to doping levels beyond the dilute limit should be developed.

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Z05: Sustainable Research Data Management (INF)

This subproject Z05 INF will establish a coherent research data management system for integrating the theoretical and experimental data in the CRC FLAIR subprojects and between the CRC partners. It focuses on workflows and dataflows by appropriately defining a common (meta-)data structure. The project will implement a hierarchical data repository for sample tracking, data sharing, and open data publication. A major part of the project is the development and implementation of a distributed electronic lab notebook system (eLabFTW) for the collection of data and metadata for reproducible workflows.

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More information on FLAIR can be found here.

The LOEWE FLAME „Fermi Level Engineering of Antiferroelectric Materials for Energy Applications” project funded by Hesse investigated how the properties of functional materials can be adjusted via their electronic structure. In particular, it aimed at (1) understanding the electronic structure of FE/AFE materials based on density functional theory and beyond, modern Berry phase theory of electric polarization, and FE-AFE transitions under homogeneous electric fields and (2) systematic calculations of phonon spectra with detailed symmetry analysis, and construction of effective Landau-type Hamiltonian.

An integrated paradigm has been developed with high throughput DFT calculations, machine learning, and CALPHAD phase diagram. It managed to bridge the gap to multi-scale simulations and to experiments with mutual validation.

While a particular goal falls on designing novel materials at the thermodynamic equilibrium with the competing phases, as well as explicit evaluation of the phase diagrams providing guidance to experimental synthesis, special focus was on magnetic phase transitions where the underlying spin-lattice dynamics were elucidated based on quantitative modeling with DFT accuracy. Special measures following the Teacher-Scholar model helped the students transform from learning to doing research, enriching their scientific pictures and languages, and thus benefited their scientific lives. With this project we established a coherent model where teaching and research were simultaneously promoted.

Hessen LOEWE 01/2014 to 12/2016

The LOEWE RESPONSE project was funded by the State of Hessen. TMM was responsible partially for the first-principles section that focused on modelling structure-property relationships in rare-earth free or rare-earth reduced permanent magnets by means of electronic structure calculations using methods that extend beyond mean-field approaches (DFT). The final goal was to efficiently optimize permanent magnets, utilizing the high-throughput methods derived based on numerical techniques from Big Data community. We worked collaboratively within a highly interdisciplinary network involving 11 partners of different departments of the TU Darmstadt.

Further information can be found at: http://www.response.tu-darmstadt.de/response/index.de.jsp