Structure‐Dependent Electrical and Magnetic Properties of Iron Oxide Composites. Issue 16 (20th May 2019)

• Record Type: Journal Article
• Authors: Lertcumfu, Narumon; Sayed, Farheen N.; Shirodkar, Sharmila N.; Radhakrishnana, Sruthi; Mishra, Avanish; Rujijanagul, Gobwute; Singh, Abhishek K.; Yakobson, Boris I.; Tiwary, Chandra S.; Ajayan, Pulickel M.
• Is Part Of: Physica status solidi. Volume 216:Issue 16(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-05-20
• Subjects: composites -- conductivity -- dielectric -- interface -- interphase -- iron oxides -- magnetism; Solid state physics -- Periodicals; Solids -- Industrial applications -- Periodicals; 530.41
• DOI: 10.1002/pssa.201801004
• Languages: English
• ISSNs: 1862-6300

Abstract

Abstract : The physical and chemical properties of polymorphs of iron oxides are utilized for electronic, energy, and biomedical applications. To design a functional material with arresting interplay at the interfaces and boundaries between polymorphs of iron oxide (Fe3 O4 – magnetite with Fe2 O3 – hematite), two different approaches of synthesis are adopted, namely, mechanical mixing and in situ growth. Unlike mechanically mixed composites, the in situ‐synthesized composites show the development of a highly distinct non‐stoichiometric, Fe21.34 O32 phase at the boundary. The atomically diffused composition at boundary is found to govern the fourfold increase in conductivity. By varying the ratio of constituent iron oxide polymorphs, the dielectric constant can be tuned and is found to be highly frequency dependent with minimum loss in tan δ plot. The inherent ferromagnetism of Fe3 O4 reveals to be retained in composite samples. Abstract : To design a functional material with arresting interplay at the interfaces and boundaries between polymorphs of iron oxide (Fe3 O4 – magnetite with Fe2 O3 – hematite), two different approaches of synthesis are adopted, namely, mechanical mixing and in situ growth. The atomically diffused composition at the boundary is found to govern the fourfold increase in conductivity.