Double helix of icosahedra structure and spin glass magnetism of the $\delta$-${\rm Co}_{2.5}{\rm Zn}_{17.5–x}{\rm Mn}_x (x = 0.4–3.5)$ pseudo-binary alloys

Mondal, Amit (author), Koželj, Primož (author), Jagličić, Zvonko (author), Meden, Anton (author), Pratim Jana, Partha (author), Dolinšek, Janez (author)

We have synthesized $\delta$-${\rm Co}_{2.5}{\rm Zn}_{17.5–x}{\rm Mn}_x (x = 0.4–3.5)$ pseudo-binary alloys of 10 different compositions by a high-temperature solid-state synthetic route, determined their crystal structures and the Mn substitution pattern, and estimated the existence range of the $\delta$-phase. The alloys crystallize in two chiral enantiomorphic space groups $P6_2$ and $P6_4$, where the basic atomic polyhedron of the chiral structure is an icosahedron and the neighboring icosahedra share vertices to form an infinitely long double helix along the hexagonal axis (like in the $\delta$-${\rm Co}_{2.5}{\rm Zn}_{17.5}$ parent binary phase). The alloys are pure $\delta$-phase up to the ${\rm Mn}$ content $x \approx 3.5$. The ${\rm Mn}$ atoms partially substitute ${\rm Zn}$ atoms at particular crystallographic sites located on the icosahedra. The study of magnetism was performed on the ${\rm Co}_{2.5}{\rm Zn}_{17.1}{\rm Mn}_{0.4}$ alloy with the lowest ${\rm Mn}$ content. Contrary to the expectation that structural chirality may induce the formation of a nontrivial magnetic state, a spin glass state with no relation to the structural chirality was found. The magnetic sublattice contains all of the necessary ingredients (randomness and frustration) for the formation of a spin glass state. Typical out-of-equilibrium dynamic phenomena of a spin system with broken ergodicity were detected below the spin freezing temperature $T_f \approx 8$ K.

• Language: English
• Keywords: chemical structure, crystal structure, nucleic acid structure, quantum mechanics, transition metals
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics; FGG - Faculty of Civil and Geodetic Engineering; FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. 10251–10263
• Numbering: Vol. 63, iss. 22
• PID: 20.500.12556/RUL-158315
• UDC: 546
• ISSN on article: 1520-510X
• DOI: 10.1021/acs.inorgchem.4c00686
• COBISS.SI-ID: 196165379
• Publication date in RUL: 05.06.2024

Record is a part of a journal

• Title: Inorganic chemistry
• Shortened title: Inorg. chem.
• Publisher: American Chemical Society
• ISSN: 1520-510X
• COBISS.SI-ID: 512805401

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: zlitine, kristalna struktura, kemična sestava, nukleinske kisline