% IMPORTANT: The following is UTF-8 encoded. This means that in the presence % of non-ASCII characters, it will not work with BibTeX 0.99 or older. % Instead, you should use an up-to-date BibTeX implementation like “bibtex8” or % “biber”. @ARTICLE{Sodernik:893187, author = {Soderžnik, Kristina Žagar and Rožman, Kristina Žužek and Komelj, Matej and Kovács, András and Diehle, Patrick and Denneulin, Thibaud and Savenko, Aleksei and Soderžnik, Marko and Kobe, Spomenka and Dunin-Borkowski, Rafal E. and Mayer, Joachim and Markoli, Boštjan and Šturm, Sašo}, title = {{M}icrostructural insights into the coercivity enhancement of grain-boundary-diffusion-processed {T}b-treated {N}d-{F}e-{B} sintered magnets beyond the core-shell formation mechanism}, journal = {Journal of alloys and compounds}, volume = {864}, issn = {0925-8388}, address = {Lausanne}, publisher = {Elsevier}, reportid = {FZJ-2021-02611}, pages = {158915 -}, year = {2021}, abstract = {We propose a dominant core-shell formation mechanism for grain-boundary-diffusion-processed (GBDP), Tb-treated, Nd2Fe14B sintered magnets. A depth-sensitive analysis of Tb-treated samples, relative to a non-GBDP Nd2Fe14B magnet, showed a $30\%$ increase of the coercivity in the central part of the magnet. A structure-chemistry-magnetic-property analysis revealed the dominant GBDP mechanism. On the surface of the Tb-treated magnet, the Tb is released from the starting precursor following a cascade of chemical reactions between the Tb oxide and the Nd and/or the Nd-Fe-B. The released Tb diffuses along the grain boundaries, forming a core-shell structure. The calculated optimum concentration for a $30\%$ increase in the coercivity was 50 ppm of Tb. Off-axis electron-holography measurements were used to quantitatively map the characteristic magnetic states of the samples, confirming a different magnetic domain structure in the shell than in the core. The magnetic induction in the core was found to be $26\%$ higher than that of the shell, which has a lower magnetic saturation due to the presence of Tb. The results show that the measured increase in the coercivity is due to a structural effect, and not the magnetic contribution of the Tb. Our results pave the way towards grain-boundary-engineering studies that can be used to increase the coercivity of Nd-Fe-B magnets for e-mobility and eco-power applications.}, cin = {ER-C-1}, ddc = {540}, cid = {I:(DE-Juel1)ER-C-1-20170209}, pnm = {535 - Materials Information Discovery (POF4-535) / ESTEEM3 - Enabling Science and Technology through European Electron Microscopy (823717) / 3D MAGiC - Three-dimensional magnetization textures: Discovery and control on the nanoscale (856538) / DFG project 405553726 - TRR 270: Hysterese-Design magnetischer Materialien für effiziente Energieumwandlung (405553726)}, pid = {G:(DE-HGF)POF4-535 / G:(EU-Grant)823717 / G:(EU-Grant)856538 / G:(GEPRIS)405553726}, typ = {PUB:(DE-HGF)16}, UT = {WOS:000624942300102}, doi = {10.1016/j.jallcom.2021.158915}, url = {https://juser.fz-juelich.de/record/893187}, }