20.500.12556/RUL-172595 Sinteza in zgoščevanje W-tipa heksaferitov Synthesis and densification of W-type hexaferrites Trajni magneti (TM) so ključni sestavni deli zelenega prehoda. Imajo osrednjo vlogo pri obnovljivi in trajnostni energiji ter mobilnosti. Najbolj zmogljivi TM temeljijo na elementih redkih zemelj (REE), medtem ko so manj zmogljivi TM feriti. Vendar pa REE zaradi tveganja pri dobavi in nestanovitnosti cen ter tudi njihovega škodljivega vpliva na okolje predstavljajo določeno stopnjo tveganja in z njo povezano iskanje alternativ. V tem kontekstu so feriti ena najpogosteje uporabljenih magnetnih materialov uporabljenih za trajne magnete, predvsem zaradi nizkih stroškov, dobre razpoložljivosti in uporabe v številnih aplikacijah. Cilj diplomske naloge je optimizacija sinteze W-tipa heksaferitov (SrZn$_2$Fe$_{16}$O$_{27}$) ter njihovo zgoščevanje. SrZn$_2$Fe$_{16}$O$_{27}$ smo sintetizirali z metodo sol-gel, ki ji je sledila kalcinacija pri različnih temperaturah in zadrževalnih časih. Najobetavnejše prahove smo zgoščevali z metodo sintranja s pulzirajočim električnim tokom brez dovedenega tlaka (p-SPS) in konvencionalno. Sintetiziranim in kalciniranim prahovom ter peletom po zgoščevanju smo določili fazno sestavo, analizirali mikrostrukturo ter magnetne lastnosti. Permanent magnets (TM) are key components of the green transition. They play a central role in renewable and sustainable energy and mobility. The highest performing TMs are based on rare earth elements (REEs), while the lower performing TMs are ferritic. However, due to supply risk and price volatility, as well as their harmful impact on the environment, REEs represent a certain level of risk and drive the search for alternatives. In this context, ferrites are one of the most commonly used magnetic materials for permanent magnets, primarily due to their low cost, good availability, and wide range of applications. This thesis aims to optimize the synthesis of W-type hexaferrites (SrZn$_2$Fe$_{16}$O$_{27}$), and their densification. SrZn$_2$Fe$_{16}$O$_{27}$ was synthesized by the sol-gel method, followed by calcination at various temperatures and durations. We densified powders with the best properties using the pressureless spark plasma sintering (p-SPS) and conventional sintering method. We determined the phase composition of the synthesized and calcined powders and pellets after densification, analysed the microstructure and magnetic properties. W-tip heksaferiti trajni magneti sinteza sintranje W-type hexaferrites permanent magnets synthesis sintering true false false Slovenski jezik Angleški jezik Diplomsko delo/naloga 2025-09-09 13:00:14 2025-09-09 13:00:18 2025-10-30 11:35:26 0000-00-00 00:00:00 2025 0 0 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 25776 255400195 Bostic_Doroteja_-_Sinteza_in_zgoscevanje_W-tipa_heksaferitov.pdf Bostic_Doroteja_-_Sinteza_in_zgoscevanje_W-tipa_heksaferitov.pdf 1 3B97639D6CCF2EDAE26A3D6E5A64F0E2 ff739f93dc1be04c1c6fcd5df4aee26f803cf38bc8dec7bc5cec614645efb1ab 03ce24a5-8d6c-11f0-9328-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=216505 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0