Development of optimum preparation conditions of Fe-deficient M-type Ca-Sr-La System hexagonal ferrite Magnet

Ching Chien Huang, Shih Hao Lin, Chin Chieh Mo, Tsung Han Hsiao, Yen Hua Tai, Yung Hsiung Hung, Chun Hao Chiu, Hsiao Hsuan Hsu, Chun Hu Cheng

Research output: Contribution to journalArticlepeer-review


In this work, an experiment was carried out to investigate the preparation condition of anosotropic Fe-deficient M-type Ca-Sr-La system ferrire with optimum magnetic and physical properties using the raw material Fe2O3 from steel industrial iron oxide waste. The compositions of the calcined ferrites were chosen according to the stoichiometry Ca1-x-yLaxSryFe10.9CozO19, where M-type singlephase calcined powder was synthesized with a composition of x = 0.45, y = 0.18 and z = 0. The effect of CaO, SiO2 and Co3O4 inter-additives on the Ca-Sr-La system ferrite was also discussed in order to obtain low-temperature sintered magnets. The magnetic properties of Br = 4570Gauss, bHc = 4320 Oe, iHc =5260 Oe and (BH)max = 5.16 MGOe were obtained for Ca-Sr-La system hard magnets with low cobalt content at 1.85wt%. The magnetic properties greats exceeds that of traditional Sr-La-Co M-type ferrite, which has been the highest grade M-type hard ferrite. The unremarkable steel industrial iron oxide waste Fe2O3 is recycled produce high-end permanent magnets under output power < 1kW, which will eventually be used in high-efficiency motors.

Original languageEnglish
Article number9277610
JournalIEEE Transactions on Magnetics
Issue number2
Publication statusAccepted/In press - 2020


  • by-product
  • Calcination
  • circular economy
  • Cobalt
  • Ferrites
  • hard ferrite
  • Iron
  • iron oxide powder
  • magnet
  • Magnetic properties
  • motor
  • Powders
  • Saturation magnetization

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering


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