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Giant magnetoimpedance effect in Fe wires
Materials Science and Engineering B86 (2001) 144– 146 www.elsevier.com/locate/mseb
Giant magnetoimpedance effect in Fe wires Jifan Hu *, Hongwei Qin Department of Physics, Shandong Uni6ersity, Jinan 250100, People’s Republic of China Accepted 3 May 2001
Abstract In the present work we report, for the first time, the giant magnetoimpedance effect in pure Fe wire with grain size of tens micrometers. The impedance as well as resistance and reactance decrease with application of d.c. magnetic fields (H B0.5 kOe) in the frequency range of 0.1–12 MHz. The magnetoimpedance ratio (Z(0)− Z(H))/Z(0) of Fe wire can reach the value of 8.4% under H=0.4 kOe at a frequency of 1 MHz. © 2001 Elsevier Science B.V. All rights reserved. Keywords: Magnetoimpedance; Iron; Magnetic field
Recently the giant magnetoimpedance (GMI) effect has attracted great attention because of its potential applications in field sensing and heads. This effect involves a sensitive change in an a.c. voltage in soft magnetic materials with the application of a small d.c. magnetic field. The GMI effect has been observed in the amorphous FeCoSiB [1,2] nanocrystalline FeCuNbSiB [3,4] FeNbB [5] FeZrB [6,7] FeHfB [6] FePCMoCuSi [8] permalloy NiFeMo [9 – 11] and the sintered
Fig. 1. The frequency dependence of the impedance Z, the resistance R and the reactance X for the Fe wire at the absence of magnetic field H=0. * Corresponding author. Tel.: +86-531-856-6143; fax: +86-531856-5167. E-mail address: [email protected] (J. Hu).
perovskite oxides La –Ba –Mn –O [12]. In the present work, we report, for the first time, the giant magnetoimpedance GMI effect in pure Fe wire with an average grain size of about 22 micrometers. The pure Fe wire of 0.12 mm diameter, 15 mm length was used in the magnetoimpedance MI measurement which was carried out using a HP4192A impedance analyzer at room temperature. AC currents and d.c. magnetic fields were applied in the direction along the wire. Fig. 1 shows the frequency dependence of the impedance Z, the resistance R and the reactance X for Fe wire at the absence of magnetic field H=0. It can be seen that above a certain frequency f * about 50 kHz, The impedance Z increases with increasing a.c. frequency, which is mainly because of the skin effect. Furthermore, the term X varies more quickly with the frequency than the term R. Fig. 2 shows the impedance Z dependence on d.c. magnetic field (HB 0.5 kOe) for Fe wire at different frequencies f=0.1, 1, 5 and 12 MHz, respectively. It is evident that the values of Z decrease with application of fields, showing negative magnetoimpedance effect. At f= 0.1 MHz, Z decreases from 0.121 to 0.115 (with increasing field from 0 to 0.444 kOe. At f= 12 MHz, Z varies from 3.002 to 2.910 (with increasing field from 0 to 0.476 kOe. Similar magnetic field dependence of the resistance and the reactance are shown in Figs. 3 and 4, respectively. The GMI effect was earlier found in the Co based amorphous, Fe-based nanocrystalline and
0921-5107/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 1 - 5 1 0 7 ( 0 1 ) 0 0 6 7 0 - 5
J. Hu, H. Qin / Materials Science and Engineering B86 (2001) 144–146
145
Fig. 2. The impedance Z dependence on the magnetic field (H B0.5 kOe) for the Fe wire.
Fig. 3. The resistance R dependence on the magnetic field (H B 0.5 kOe) for the Fe wire.
Mn based perovskite sintered oxides. Our present results show that the GMI effect also occurs in Fe wires. The a.c. frequency dependence of the magnetoimpedance ratio (Z(0) −Z(0.4 kOe))/Z(0), the magnetoresistance ratio (R(0) −R(0.4 kOe))/R(0) and magnetoreactance ratio (X(0) −X(0.4 kOe))/X(0) are shown in Fig. 5. The value of magnetoimpedance ratio (Z(0)− Z(0.4 kOe))/Z(0) at 0.1 MHz is 4.1%. With increasing frequency, the magnetoimpedance ratio increases at first, undergoes a peak with the value of 8.4% at 1 MHz, and finally decreases again with further
increase of frequency. The value of magnetoimpedance ratio is 2.6% at 12 MHz. Similar frequency dependence has also been found for the case of the magnetoresistance ratio (R(0)− R(0.4 kOe))/R(0). The value of the magnetoresistance ratio is 16.6% at 5 MHz. In contrast, the magnetoreactance (X(0)− X(0.4 kOe))/X(0) decreases monotonically from 16.6 to 2% with increasing frequency from 0.1 to 12 MHz. Similar behavior has been observed in a NiFeMo permalloy [11]. In summary, in the present work the giant magnetoimpedance effect in pure Fe wire is reported. Since
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J. Hu, H. Qin / Materials Science and Engineering B86 (2001) 144–146
Fig. 4. The reactance X dependence on the magnetic field (H B 0.5 kOe) for the Fe wire.
the Fe wire can be fabricated in large amounts industrially and is very cheap, the GMI effect of Fe wires may be of great interest for many practical applications.
Acknowledgements This work was supported by the Cheung Kong Scholars Programme and the Trans-Century Research Foundation of Education Ministry of China. References
Fig. 5. The ac frequency dependence of the magnetoimpedance ratio (Z(0)− Z(0.4 kOe))/Z(0), the magnetoresistance ratio (R(0) −R(0.4 kOe))/R(0) and magnetoreactance ratio (X(0)− X(0.4 kOe))/X(0) for the Fe wire.
.
[1] K. Mohri, K. Kawashima, T. Kohzawa, Y. Yoshida, L.V. Panina, IEEE Trans. Magn. 28 (1992) 3150. [2] R.S. Beach, A.E. Berkowitz, Appl. Phys. Lett. 76 (1994) 6198. [3] R.L. Sommer, C.L. Chien, Appl. Phys. Lett. 67 (1995) 3346. [4] G.V. Kurlyanskaya, J.M. Garcı´a-Beneytez, M. Va´ zquez, J.P. Sinnecker, V.A. Lukshina, A.P. Potapov, J. Appl. Phys. 83 (1998) 6581. [5] J. Hu, S. Zhou, W. Chen, Y. Wang, Solid State Commun. 109 (1999) 661. [6] M. Knobel, H. Chiriac, J.P. Sinnecker, S. Marinescu, T.A. Ovari, A. Inoue, Sensors and Actuators A 59 (1997) 256. [7] H. Qin, J. Func. Mater. 31 (2000) 40. [8] J. Hu, H. Qin, S. Zhou, Y. Wang, Z. Wang, Mater. Sci. Eng., B, 83 (2001) 24. [9] J. Hu, Y. Wang, Z. Wang, S. Zhou, Mater. Sci. Eng. B77 (2000) 15. [10] M. Va´ zquez, J.M. Garcı´a-Beneytez, J.P. Sinnecker, Lin Li, Appl. Phys. 83 (1998) 578. [11] J. Hu, H. Qin, S. Zhou, Y. Wang, Z. Wang, Mater. Trans. JIM 41 (2000) 1589. [12] J. Hu, H. Qin, Y. Zhang, Mater. Sci. Eng. B B77 (2000) 280.
Giant magnetoimpedance effect in Fe wires Jifan Hu *, Hongwei Qin Department of Physics, Shandong Uni6ersity, Jinan 250100, People’s Republic of China Accepted 3 May 2001
Abstract In the present work we report, for the first time, the giant magnetoimpedance effect in pure Fe wire with grain size of tens micrometers. The impedance as well as resistance and reactance decrease with application of d.c. magnetic fields (H B0.5 kOe) in the frequency range of 0.1–12 MHz. The magnetoimpedance ratio (Z(0)− Z(H))/Z(0) of Fe wire can reach the value of 8.4% under H=0.4 kOe at a frequency of 1 MHz. © 2001 Elsevier Science B.V. All rights reserved. Keywords: Magnetoimpedance; Iron; Magnetic field
Recently the giant magnetoimpedance (GMI) effect has attracted great attention because of its potential applications in field sensing and heads. This effect involves a sensitive change in an a.c. voltage in soft magnetic materials with the application of a small d.c. magnetic field. The GMI effect has been observed in the amorphous FeCoSiB [1,2] nanocrystalline FeCuNbSiB [3,4] FeNbB [5] FeZrB [6,7] FeHfB [6] FePCMoCuSi [8] permalloy NiFeMo [9 – 11] and the sintered
Fig. 1. The frequency dependence of the impedance Z, the resistance R and the reactance X for the Fe wire at the absence of magnetic field H=0. * Corresponding author. Tel.: +86-531-856-6143; fax: +86-531856-5167. E-mail address: [email protected] (J. Hu).
perovskite oxides La –Ba –Mn –O [12]. In the present work, we report, for the first time, the giant magnetoimpedance GMI effect in pure Fe wire with an average grain size of about 22 micrometers. The pure Fe wire of 0.12 mm diameter, 15 mm length was used in the magnetoimpedance MI measurement which was carried out using a HP4192A impedance analyzer at room temperature. AC currents and d.c. magnetic fields were applied in the direction along the wire. Fig. 1 shows the frequency dependence of the impedance Z, the resistance R and the reactance X for Fe wire at the absence of magnetic field H=0. It can be seen that above a certain frequency f * about 50 kHz, The impedance Z increases with increasing a.c. frequency, which is mainly because of the skin effect. Furthermore, the term X varies more quickly with the frequency than the term R. Fig. 2 shows the impedance Z dependence on d.c. magnetic field (HB 0.5 kOe) for Fe wire at different frequencies f=0.1, 1, 5 and 12 MHz, respectively. It is evident that the values of Z decrease with application of fields, showing negative magnetoimpedance effect. At f= 0.1 MHz, Z decreases from 0.121 to 0.115 (with increasing field from 0 to 0.444 kOe. At f= 12 MHz, Z varies from 3.002 to 2.910 (with increasing field from 0 to 0.476 kOe. Similar magnetic field dependence of the resistance and the reactance are shown in Figs. 3 and 4, respectively. The GMI effect was earlier found in the Co based amorphous, Fe-based nanocrystalline and
0921-5107/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 1 - 5 1 0 7 ( 0 1 ) 0 0 6 7 0 - 5
J. Hu, H. Qin / Materials Science and Engineering B86 (2001) 144–146
145
Fig. 2. The impedance Z dependence on the magnetic field (H B0.5 kOe) for the Fe wire.
Fig. 3. The resistance R dependence on the magnetic field (H B 0.5 kOe) for the Fe wire.
Mn based perovskite sintered oxides. Our present results show that the GMI effect also occurs in Fe wires. The a.c. frequency dependence of the magnetoimpedance ratio (Z(0) −Z(0.4 kOe))/Z(0), the magnetoresistance ratio (R(0) −R(0.4 kOe))/R(0) and magnetoreactance ratio (X(0) −X(0.4 kOe))/X(0) are shown in Fig. 5. The value of magnetoimpedance ratio (Z(0)− Z(0.4 kOe))/Z(0) at 0.1 MHz is 4.1%. With increasing frequency, the magnetoimpedance ratio increases at first, undergoes a peak with the value of 8.4% at 1 MHz, and finally decreases again with further
increase of frequency. The value of magnetoimpedance ratio is 2.6% at 12 MHz. Similar frequency dependence has also been found for the case of the magnetoresistance ratio (R(0)− R(0.4 kOe))/R(0). The value of the magnetoresistance ratio is 16.6% at 5 MHz. In contrast, the magnetoreactance (X(0)− X(0.4 kOe))/X(0) decreases monotonically from 16.6 to 2% with increasing frequency from 0.1 to 12 MHz. Similar behavior has been observed in a NiFeMo permalloy [11]. In summary, in the present work the giant magnetoimpedance effect in pure Fe wire is reported. Since
146
J. Hu, H. Qin / Materials Science and Engineering B86 (2001) 144–146
Fig. 4. The reactance X dependence on the magnetic field (H B 0.5 kOe) for the Fe wire.
the Fe wire can be fabricated in large amounts industrially and is very cheap, the GMI effect of Fe wires may be of great interest for many practical applications.
Acknowledgements This work was supported by the Cheung Kong Scholars Programme and the Trans-Century Research Foundation of Education Ministry of China. References
Fig. 5. The ac frequency dependence of the magnetoimpedance ratio (Z(0)− Z(0.4 kOe))/Z(0), the magnetoresistance ratio (R(0) −R(0.4 kOe))/R(0) and magnetoreactance ratio (X(0)− X(0.4 kOe))/X(0) for the Fe wire.
.
[1] K. Mohri, K. Kawashima, T. Kohzawa, Y. Yoshida, L.V. Panina, IEEE Trans. Magn. 28 (1992) 3150. [2] R.S. Beach, A.E. Berkowitz, Appl. Phys. Lett. 76 (1994) 6198. [3] R.L. Sommer, C.L. Chien, Appl. Phys. Lett. 67 (1995) 3346. [4] G.V. Kurlyanskaya, J.M. Garcı´a-Beneytez, M. Va´ zquez, J.P. Sinnecker, V.A. Lukshina, A.P. Potapov, J. Appl. Phys. 83 (1998) 6581. [5] J. Hu, S. Zhou, W. Chen, Y. Wang, Solid State Commun. 109 (1999) 661. [6] M. Knobel, H. Chiriac, J.P. Sinnecker, S. Marinescu, T.A. Ovari, A. Inoue, Sensors and Actuators A 59 (1997) 256. [7] H. Qin, J. Func. Mater. 31 (2000) 40. [8] J. Hu, H. Qin, S. Zhou, Y. Wang, Z. Wang, Mater. Sci. Eng., B, 83 (2001) 24. [9] J. Hu, Y. Wang, Z. Wang, S. Zhou, Mater. Sci. Eng. B77 (2000) 15. [10] M. Va´ zquez, J.M. Garcı´a-Beneytez, J.P. Sinnecker, Lin Li, Appl. Phys. 83 (1998) 578. [11] J. Hu, H. Qin, S. Zhou, Y. Wang, Z. Wang, Mater. Trans. JIM 41 (2000) 1589. [12] J. Hu, H. Qin, Y. Zhang, Mater. Sci. Eng. B B77 (2000) 280.