New applications of nanocrystalline Fe(Co-Fe)-Hf-O magnetic films to micromagnetic devices

T. Sato, Y. Miura, S. Matsumura, K. Yamasawa, S. Morita, Y. Sasaki, T. Hatanai, A. Makino

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


New applications of high resistivity magnetic films, such as Fe-Hf-O and Co-Fe-Hf-O as thin film inductors and flux gate magnetic sensors, were investigated. These soft magnetic films with nanocrystalline structure and high resistivity were deposited on glass substrate by using the oxygen reactive sputtering method. Planar sandwich thin film inductors developed by using Fe-Hf-O or Co-Fe-Hf-O films had a higher quality factor than that of an amorphous Co-Ta-Hf film inductor. The dc-dc converter using the Fe(Co-Fe)-Hf-O film inductor had higher conversion efficiency. These high resistivity magnetic films were also applied to a flux gate magnetic sensor operated at high frequencies over 1 MHz. Both high frequency excitation and high permeability (owing to the low eddy current loss) enabled us to increase the sensitivity, e.g., 39 mV/Oe/turn at 5 MHz when using a 3 μm thick Fe-Hf-O film (12x6 mm2 area).

Original languageEnglish
Pages (from-to)6658-6660
Number of pages3
JournalJournal of Applied Physics
Issue number11
Publication statusPublished - 1998
Externally publishedYes

ASJC Scopus subject areas

  • Physics and Astronomy(all)


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