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Controlling the magnetic structure in W-type hexaferrites

ABSTRACT: Using neutron powder diffraction on W-type hexaferrites, planar magnetic ordering described in Cm′cm′ was found for SrCo2Fe16O27 and SrCoZnFe16O27, while SrZn2Fe16O27 had uniaxial ordering described in P63/mm′c′. Thermomagnetic measurements above room temperature also indicated magnetic transitions for SrCo2Fe16O27 and SrCoZnFe16O27. W-type hexaferrites with varied Co/Zn ratios were synthesized and the magnetic order was investigated using neutron powder diffraction. In SrCo2Fe16O27 and SrCoZnFe16O27 a planar (Cm′cm′) magnetic ordering was found, rather than the uniaxial ordering (P63/mm′c′) found in SrZn2Fe16O27 which is common in most W-type hexaferrites. In all three studied samples, non-collinear terms were present in the magnetic ordering. One of the non-collinear terms is common to the planar ordering in SrCoZnFe16O27 and uniaxial ordering in SrZn2Fe16O27, which could be a sign of an imminent transition in the magnetic structure. The thermomagnetic measurements revealed magnetic transitions at 520 and 360 K for SrCo2Fe16O27 and SrCoZnFe16O27, and Curie temperatures of 780 and 680 K, respectively, while SrZn2Fe16O27 showed no transition but a Curie temperature at 590 K. This leads to the conclusion that the magnetic transition can be adjusted by fine-tuning the Co/Zn stoichiometry in the sample.

SUBMITTER: Mørch M

PROVIDER: S-EPMC10241064 | biostudies-literature | 2023 Apr

REPOSITORIES: biostudies-literature

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