Hopkinson Effect Study in Spinel and Hexagonal Ferrites

Jozef Sláma 1 , Martin Šoka 1 , Anna Grusková 2 , Alvaro Gonzalez 3 , and Vladimír Jančárik 1
  • 1 Department of Electromagnetic Theory, Slovak University of Technology, Ilkovičova 3, 812 19 Bratislava, Slovakia
  • 2 Department of Electrotechnology, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology, Ilkovičova 3, 812 19 Bratislava, Slovakia
  • 3 Facultad de Ingeniera, Universidad Autnoma de Baja California, México

Hopkinson Effect Study in Spinel and Hexagonal Ferrites

The magnetic susceptibility shows a Hopkinson peak just below the Curie temperature TC when heating the selected hexagonal and spinel ferrite samples. It is proposed that this peak can be associated with a transition from stable magnetic state to super-paramagnetic relaxation above the blocking temperature up to the TC. The Hopkinson effect results are compared with SEM micrographs of both studied hexagonal and spinel ferrites.

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