Materials Transactions Online

Materials Transactions, Vol.59 No.04 (2018) pp.585-589
© 2018 The Japan Institute of Metals and Materials

Tunnel-Type Magneto-Dielectric Effect and Its Annealing Study in Co-SiO2 Granular Films

Yang Cao1, Nobukiyo Kobayashi2, Shigehiro Ohnuma1, 2 and Hiroshi Masumoto1

1Frontier Research Institute for Interdisciplinary Sciences, Tohoku University, Sendai 980-8578, Japan
2Research Institute for Electromagnetic Materials, Sendai 982-0807, Japan

Tunnel-type magneto-dielectric (TMD) effect arising from the spin-dependent quantum tunneling between nano-sized granular pairs, has opened up new route for room temperature magnetoelectric fields. We first investigated the TMD properties in metal-oxide (Co-SiO2) granular films and their annealing effect in this work. Results show that the films exhibit a TMD ratio ($\Delta \varepsilon '/\varepsilon '_{0}$) of 1% with high electrical resistivity of >108 µΩ·m and intermediate optical transmittance in Co0.24-(SiO2)0.76 films. Annealing investigations suggest that the samples remain TMD response up to 573 K, and further increment in annealing temperature leads to the inter-diffusion between Co and SiO2 interfaces, thus producing the increasing oxidation of metallic Co. This study demonstrates the possibility of TMD effect in metal-oxide composite materials, and may be desirable for a variety of other wide oxide-based candidates for magnetoelectric device applications.


(Received 2017/12/14; Accepted 2018/01/30; Published 2018/03/25)

Keywords: granular nano-composites, magneto-dielectric properties, annealing effect

PDF(member)PDF (member) PDF(organization)PDF (organization) Order DocumentOrder Document Table of ContentsTable of Contents


  1. Wang J., Neaton J.B., Zheng H., Nagarajan V., Ogale S.B., Liu B., Viehland D., Vaithyanathan V., Schlom D.G., Waghmare U.V., Spaldin N.A., Rabe K.M., Wuttig M. and Ramesh R.: Science 299 (2003) 1719-1722.
  2. Ikeda N., Ohsumi H., Ohwada K., Ishii K., Inami T., Kakurai K., Murakami Y., Yoshii K., Mori S., Horibe Y. and Kito H.: Nature 436 (2005) 1136-1138.
  3. Kimura T., Goto T., Shintani H., Ishizaka K., Arima T. and Tokura Y.: Nature 426 (2003) 55-58.
  4. Castel V. and Brosseau C.: Appl. Phys. Lett. 92 (2008) 233110.
  5. Martins P., Silva D.P., Silva M. and Lanceros-Mendez S.: Appl. Phys. Lett. 109 (2016) 112905.
  6. Beloborodov I.S., Lopatin A.V., Vinokur V.M. and Efetov K.B.: Rev. Mod. Phys. 79 (2007) 469-518.
  7. Sakai S., Yakushiji K., Mitani S., Sugai I., Takanashi K., Naramoto H., Avramov P.V., Lavrentiev V., Narumi K. and Maeda Y.: Mater. Trans. 48 (2007) 754-758.
  8. Kobayashi N., Ohnuma S., Fujimori H. and Masumoto T.: J. Japan Inst. Metals 76 (2012) 375-379.
  9. Kobayashi N., Ohnuma S., Masumoto T. and Fujimori H.: Mater. Trans., JIM 39 (1998) 679-683.
  10. Kobayashi N., Masumoto H., Takahashi S. and Maekawa S.: Nat. Commun. 5 (2014) 4417.
  11. Kobayashi N., Iwasa T., Ishida K. and Masumoto H.: J. Appl. Phys. 117 (2015) 014101.
  12. Cao Y., Umetsu A., Kobayashi N., Ohnuma S. and Masumoto H.: Appl. Phys. Lett. 111 (2017) 122901.
  13. Cao Y., Kobayashi N., Zhang Y.W., Ohnuma S. and Masumoto H.: Appl. Phys. Lett. 110 (2017) 072902.
  14. Cao Y., Kobayashi N., Zhang Y.W., Ohnuma S. and Masumoto H.: J. Appl. Phys. 122 (2017) 133903.
  15. Jiang Z.S., Jin G.J., Ji J.T., Sang H. and Du Y.W.: J. Appl. Phys. 78 (1995) 439-441.
  16. Sankar S., Berkowitz A.E. and Smith D.J.: Appl. Phys. Lett. 73 (1998) 535-537.
  17. Denardin J.C., Pakhomov A.B., Knobel M., Liu H. and Zhang X.X.: J. Phys.: Condens. Matter 12 (2000) 3397-3399.
  18. Unpublished results.
  19. Inoue J. and Maekawa S.: Phys. Rev. B 53 (1996) R11927-R11929.


© 2018 The Japan Institute of Metals and Materials
Comments to us :