TY - JOUR
T1 - Effect of Ar-N2 Sputtering Gas on Structure and Tunneling Magnetodielectric Effect in Co-(Si-N) Nanogranular Films
AU - Uchiyama, T.
AU - Cao, Y.
AU - Kijima-Aoki, H.
AU - Ikeda, K.
AU - Kobayashi, N.
AU - Ohnuma, S.
AU - Masumoto, H.
N1 - Publisher Copyright:
© 1965-2012 IEEE.
PY - 2023/11/1
Y1 - 2023/11/1
N2 - We have investigated the effect of N2 fraction x in Ar-N2 sputtering gas on the tunneling magnetodielectric (TMD) effect in Co-(Si-N) nanogranular films. Co-(Si-N) films were deposited by co-sputtering Co and Si3N4 targets in Ar- x vol.%N2 mixture gas with different N2 gas fractions x of 0-30. All deposited films had a nanogranular structure composed of Co nanogranules with a diameter of 1-3 nm embedded in a Si-N matrix. We realized the TMD effect in the films for x ≥3.3 , and the film deposited in Ar-6.6 vol.%N2 gas showed the highest dielectric variations in a magnetic field. For 3.3≤ x ≤10 , TMD peak frequency f_ TMD decreased from 17 to 40 kHz with increasing x because of the increase in intergranular spacing s. On the other hand, for 10 < x ≤30 , f_ TMD increased from 40 kHz to 3.3 MHz as x increased since both s in the out-of-plane direction and \beta , which indirectly represents the measure of the distribution of s , decreased. This study provides a new way to tailor the frequency response of the TMD effect.
AB - We have investigated the effect of N2 fraction x in Ar-N2 sputtering gas on the tunneling magnetodielectric (TMD) effect in Co-(Si-N) nanogranular films. Co-(Si-N) films were deposited by co-sputtering Co and Si3N4 targets in Ar- x vol.%N2 mixture gas with different N2 gas fractions x of 0-30. All deposited films had a nanogranular structure composed of Co nanogranules with a diameter of 1-3 nm embedded in a Si-N matrix. We realized the TMD effect in the films for x ≥3.3 , and the film deposited in Ar-6.6 vol.%N2 gas showed the highest dielectric variations in a magnetic field. For 3.3≤ x ≤10 , TMD peak frequency f_ TMD decreased from 17 to 40 kHz with increasing x because of the increase in intergranular spacing s. On the other hand, for 10 < x ≤30 , f_ TMD increased from 40 kHz to 3.3 MHz as x increased since both s in the out-of-plane direction and \beta , which indirectly represents the measure of the distribution of s , decreased. This study provides a new way to tailor the frequency response of the TMD effect.
KW - Cobalt-silicon nitride
KW - nanogranular film
KW - sputtering method
KW - tunnel magnetodielectric effect
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U2 - 10.1109/TMAG.2023.3283530
DO - 10.1109/TMAG.2023.3283530
M3 - Article
AN - SCOPUS:85161582821
SN - 0018-9464
VL - 59
JO - IEEE Transactions on Magnetics
JF - IEEE Transactions on Magnetics
IS - 11
M1 - 2800705
ER -