1. Ferrite-based magnets by high pressure consolidationCesár De Julián Fernández, Blaž Belec, Aleksander Učakar, Petra Jenuš, 2023, objavljeni povzetek znanstvenega prispevka na konferenci Opis: M-type hexaferrite magnets constitute together the rare-earth magnets the most employed magnets in the
world. Even if ferrite magnets have smaller energy product and lower magnetization saturation than rare-earth
permanent magnets (PMs), currently ferrite magnets represent the most widely used PMs, covering 80% of the
PM market production [1,2]. Recently, a strong effort is being performed to improve the magnetic properties
of ferrites with the scope of substituting partially rare-earth magnets. Most of the strategies involve the
nanostructuration of the ferrites and/or the development of hybrid compounds [3]. A bottleneck for the
production of these magnets is that standard sintering process requires high temperatures and oxidizing
atmosphere that produces the destruction of the nanostructure and several chemical changes. Different novel
strategies as out-of-equilibrium or cold sintering processes are mainly considered[2,4].
In our presentation we will show the production of dense ferrite-based magnets by high pressure multi-Anvil
press at low temperatures. This press applies quasi-isotropic pressures in the range up to 20 GPa and
temperatures up to 1200°C. We demonstrate that the consolidation of micrometric hexaferrite (SrFe12O19)
powders is possible at temperatures below 1000°C, below the standard sintering temperatures. In addition,
dense hybrid magnets were obtained composed of micrometric hexaferrites and soft high magnetization metal
Fe or FeCo NPs applying pressures up to 6 GPa and low temperatures (250°C). A deep study, including
structural, morphological and magnetic characterizations, has been performed to determine the influence of the
temperature and pressure consolidation conditions in the properties of these novel magnets. Magnetic
characterizations show that hybrid magnets exhibit larger magnetization than ferrites and single step hysteresis
loops. Single Point Detection characterizations indicate that the anisotropy field of the hybrid magnets is similar
to that of the ferrite magnets. These results suggest that the two moieties componing the high pressure
consolidated magnets have similar properties than the original micro and nano powders, but they are magnetic
coupled during the reversal process. High pressure consolidation appears as a promising technique to obtain
nano-based metal-oxide hybrid magnets with promising hard properties. Ključne besede: ferrite magnets, high pressure consolidation, low temperatures Objavljeno v RUNG: 19.10.2023; Ogledov: 789; Prenosov: 5 Povezava na datoteko Gradivo ima več datotek! Več... |
2. |
3. |
4. Magnetic performance of SrFe12O19-Zn0.2Fe2.8O4 hybrid magnets prepared by Spark Plasma SinteringPetra Jenuš, Aleksander Učakar, S. Repše, Claudio Sangregorio, Mikkele Petrecca, M Albino, Cesar de Julian Fernandez, Blaž Belec, 2021, izvirni znanstveni članek Ključne besede: magnets, hybrid magnets, ferrites Objavljeno v RUNG: 26.01.2021; Ogledov: 2497; Prenosov: 0 Gradivo ima več datotek! Več... |
5. |
6. |
7. Determination of Dissolved Iron Redox Species in Freshwater Sediment using DGT Technique Coupled to BDSHanna Budasheva, Aleksander Kravos, Dorota Korte, Arne Bratkič, Yue Gao, Mladen Franko, 2019, izvirni znanstveni članek Opis: In this work we have developed a novel method for determination of iron redox species by the use of diffusive gradients in thin-film (DGT) technique coupled to photothermal beam deflection spectroscopy (BDS). The combination of both methods achieved low limit of detection (LOD) of 0.14 μM for Fe (II) ions. The total Fe concentration determined in the Vrtojbica river sediment (Slovenia, Rožna Dolina, 5000 Nova Gorica) was 49.3 μgL–1. The Fe (II) and Fe (III) concentra- tion amounted to 12.8 μgL–1 and 39.9 μgL–1, respectively. Such an approach opens new opportunities for monitoring the content of iron species in natural waters and sediments and provides highly sensitive chemical analysis and an accurate qualitative and quantitative characteristic of the materials under study. Ključne besede: Beam deflection spectroscopy, diffusive gradients in thin-film technique, iron redox species, photothermal techniques, sediment Objavljeno v RUNG: 26.02.2019; Ogledov: 3720; Prenosov: 114 Celotno besedilo (452,58 KB) |
8. |
9. |
10. Marketing izdelkov iz furnirjaAleksander Boškin, 2006, diplomsko delo Opis: V diplomski nalogi smo celovito preučili marketing izdelkov iz furnirja, opravili smo podrobno tržno raziskavo, kjer smo analizirali obstoječe odjemalce ter anketirali potencialne odjemalce. Najprej smo na podlagi pridobljenega znanja in teoretičnih osnov predstavili pojma raziskava trga ter razvoj in uvajanje novega izdelka na trg. V nadaljevanju naloge smo predstavili izdelke, ki so predmet raziskave, načrtovali in izvedli natančno raziskavo trga za omenjene izdelke in opredelili položaj obravnavane organizacije na slovenskem trgu. V naslednjem poglavju smo obravnavali koncept segmentiranja in pozicioniranja izdelkov z opisom marketinškega spleta. Posebno pozornost smo namenili določanju možnih odjemalcev za nov izdelek, ter določanju ciljnih skupin za katere smo analizirali njihove značilnosti in potrebe. Z izsledki naloge z uporabo pravilno načrtovane politike in izbrane marketinške strategije bomo pripomogli k boljši prodaji izdelkov iz furnirja. Ključne besede: diplomske naloge, marketing, tržne raziskave, izdelki, furnir Objavljeno v RUNG: 15.10.2013; Ogledov: 5913; Prenosov: 445 Povezava na celotno besedilo Gradivo ima več datotek! Več... |