One-step synthesis of High-Entropy Oxides (HEOs) in a Flat Premixed Droplet-Seeded Flame (FPDSF)☆
POWDER TECHNOLOGY, cilt.484, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 484
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.powtec.2026.122917
- Dergi Adı: POWDER TECHNOLOGY
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Applied Science & Technology Source, Chemical Abstracts Core, Chimica, Compendex, EMBASE, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Dokuz Eylül Üniversitesi Adresli: Evet
Özet
A cost-effective Flat Premixed Droplet-Seeded Flame (FPDSF) method enables the one-step synthesis and deposition of High-Entropy Oxides (HEOs) from water-soluble precursors, using a facility to stabilize premixed flames of gas reactants homogeneously seeded with micron-sized droplets of a precursor solution. Particle synthesis takes place during the desired advection time in the nearly homogeneous post-flame environment, whose temperature and composition can be selected according to the synthesis needs. A homogeneous crystalline (Fe,Ni,Mn,Co,Cr)3O4 HEO powder, which is of interest as a catalyst, is thermophoretically deposited after describing the challenges encountered in synthesizing a (Fe,Ni,Mn,Co,Cu)3O4 HEO, which yields the deposition of aggregates with sub-stoichiometric Cu content mixed with segregated CuO nanoparticles. Microscopy measurements reveal that all deposited samples consist of nanosized primary particles composing micron-sized spheroidal aggregates, with EDX mapping evidencing an overall excellent stoichiometric mixing of all elements, except for the Cu partial segregation. Importantly, XRD analyses show that the Cr-containing material, as synthesized, consists of a single uniform crystalline phase of the targeted (Fe,Ni,Mn,Co,Cr)3O4 HEO with the desired cubic spinel structure (Fd3m), with negligible background from amorphous phases. All but one of the XRD peaks of such a desired crystalline phase are also observed in the deposited ((Fe,Ni,Mn,Co)0.63,Cu0.37)3O4 material, in addition to those of nanosized CuO, indicating that it consists of a Cu-substoichiometric HEO mixed with segregated CuO nanoparticles. Regardless, the deposition of such a partially imperfect product provides a cautionary tale about possible segregation of the most volatile element(s) when synthesizing any multicomponent material in flames.