Frequency response of common lead and shield type magnetic tunneling junction head

K. Shimazawa, J. J. Sun, N. Kasahara, K. Sato, T. Kagami, S. Saruki, O. Redon, Y. Fujita, T. Umehara, J. Syoji, S. Araki, M. Matsuzaki

Research output: Contribution to journalConference articlepeer-review

17 Citations (Scopus)


In this work, the frequency response in magnetic tunnel junction (MTJ) heads was studied. Both stray capacitance and junction resistance, forming a low-pass-filter, have to be reduced to improve the cutoff frequency in MTJ heads. By employing an Ar gas cluster ion beam (GCIB) process, junctions grown on the magnetic shield show a resistance area product as low as 3.6 Ωμm2 and tunneling magneto-resistance over 14%. The dominant capacitance in common lead and shield MTJ heads was found mainly resulting from the shield-to-shield spacing, whose capacitance can be reduced by using an SiO2 gap layer instead of Al2O3 layer and thus leading to an improved frequency response. Simple analysis indicates that a read amplifier design with low impedance could be helpful to realize a high data transfer rate, and a rate of around 800 Mbps for 100 Gbits/in2 recording system can be thus expected.

Original languageEnglish
Pages (from-to)1684-1686
Number of pages3
JournalIEEE Transactions on Magnetics
Issue number4 I
Publication statusPublished - 2001 Jul
Externally publishedYes
Event8th Joint Magnetism and Magnetic Materials -International Magnetic Conference- (MMM-Intermag) - San Antonio, TX, United States
Duration: 2001 Jan 72001 Jan 11


  • Common lead and shield
  • Cut off frequency
  • Data transfer rate
  • Input impedance
  • Magnetic recording/magnetic tunnel junction heads
  • Stray capacitance

ASJC Scopus subject areas

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


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