Dynamics of magnetization reversal and directional anisotropies in magnetic nanostructures

• Applicant: Professorin Dr. Sabrina Disch
• Subject Area: Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 277603973

The fundamental understanding of magnetic anisotropy and magnetic interactions in nanostructured materials is indispensable for the rational development of nanomaterials for future applications, ranging from nanoprobes with tailored magnetization relaxation as useful for medical applications to magnetic entities with optimized magnetic switching behavior for mass data storage or sensor materials. The Emmy Noether Project ‚Dynamics of magnetization reversal and directional anisotropies in magnetic nanostructures‘ studies the directional anisotropy and magnetization dynamics in magnetic nanostructures of different geometries and compositions, with the goal to achieve a fundamental understanding of the microscopic influence of shape anisotropy, interface phenomena and dipolar interactions on the magnetization reversal. This proposal extends the project by two additional subprojects that fit into the original scope and further develop our activities in the direction of dynamic interparticle structure formation and the tunability of intraparticle spin disorder. In detail, we will address the influence of nanoparticle shape on the superstructure formation in colloidal dispersions during application of high-frequency AC magnetic fields comparable to the clinic conditions for magnetic hyperthermia. Superstructure formation has been suggested beneficial for magnetic heating as it affects the magnetization reversal. Considering its strong influence on structure formation in static field conditions, a significant effect of the nanoparticle shape and size on the dynamic structure formation is expected. With the second subproject, we will address the relationship between thermal post-synthesis processing and the internal spin disorder and related disorder energy distribution in ferrite nanoparticles. Based on our recent insight into the field dependence of magnetic disorder in ferrite nanoparticles, we aim now to elucidate the relevance of magnetic disorder for the dynamic magnetization relaxation.

• DFG Programme: Independent Junior Research Groups