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PVDF laminate composites
Materials Science and Engineering B99 (2003) 211 /213 www.elsevier.com/locate/mseb
The magnetoelectric properties of lead zirconate titanate/terfenol-D/ PVDF laminate composites Ning Cai, Junyi Zhai, Li Liu, Yuanhua Lin, Ce-Wen Nan * State Key Laboratory of New Ceramics and Fine Progressing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, People’s Republic of China Received 14 June 2002; received in revised form 8 October 2002; accepted 21 October 2002
Abstract Lead zirconate titanate (PZT-5)/Tb0.28Dy0.72Fe1.95 (Terfenol-D)/poly vinylidene fluoride (PVDF) laminate composites were prepared using stacking and heat-pressing together one Terfenol-D/PVDF disk and two layers of PZT/PVDF. The dependence of the magnetoelectric conversion coefficient (dE /dH ) of these composites on the value of applied dc magnetic field, thickness of layers and frequency of the ac magnetic field has been studied systematically. The results indicate that the dE /dH can reach the maximum 126.84 mV/cm.Oe when the layers thickness ratio of PZT/PVDF to Terfenol-D/PVDF is 0.375/1.0. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Composite; Magnetoelectric effect; Laminate
1. Introduction Magnetoelectric effect (ME) is a coupled (or cross) two-field effect, in which the application of either a magnetic field or an electrical field induces an electric polarization as well as a magnetization [1]. In 1894 Pierre Curie predicted it prophetically first on the basis of symmetry considerations [2]. The experimental search began in Russia in the 1950’s with the replacement of some of the d0 B cations in ferroelectric perovskite oxides by magnetic dn cations [3]. Until 1960 /1961, the linear ME effect was only experimentally observed in the antiferroelectric Cr2O3 crystal [4,5]. Nickel iodine boracite (Ni3B7O13I) was discovered to be ferromagnetic ferroelectric in 1966 [6]. This was followed by the synthesis of many more multiferroic boracite compounds. Such magnetoelectric composites are exploited as sensors, waveguides, modulators, swiches, phase inverter, rectifier, etc., and find substantial application in the radioelectronics and microwave electronics[7,8]. For example, magetoelectric materials will be useful in * Corresponding author. Tel./fax: /86-10-6277-3587. E-mail address: [email protected] (C.-W. Nan).
microwave devices and high power electric transmission systems, which can measure the electromagnetic leak signal generated from these devices accurately. In addition, a magnetoelectric sensor will be an alternative tool of the Hall sensor for magnetic field measurement[9]. Jungho RYU [6] etc. have reported the big ME coefficient 5.9V mV/cm.Oe, but the method they used is very complex and need long time. In this paper, a simple method is introduced to fabricate laminated composites of lead zirconate titanate (PZT)/ Tb0.28Dy0.72Fe1.95 (Terfenol-D)/poly vinylidene fluoride (PVDF), which can reduce the time of producing. And their properties have been investigated detailed.
2. Experimental procedure As magnetostrictive materials, high magnetostrictive property under a relative low magnetic field bias is preferred. In order to achieve the high value of magnetoelectric effect Tb0.28Dy0.72Fe1.95 (Terfenol-D, /50 mm) alloy was employed as the magnetostrictive phase in our composites. As for the piezoelectric phase, PZT was chosen to prepare the composites due to its high
0921-5107/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved. doi:10.1016/S0921-5107(02)00534-2
212
N. Cai et al. / Materials Science and Engineering B99 (2003) 211 /213 Table 1 The composition of different samples
Fig. 1. Schematic of samples’ structure.
piezoelectric constants. Additionally, PVDF is employed to bend these two components. PZT (57vol.%, powder size of /5 mm piezoelectric constant d33 is 330) and Terfenol-D (57 vol.%, powder size of /50 mm) were mixed with PVDF (43 vol.%, powder) separately, and than sample pallets were heatpressed to be size of f 15 /2 mm according to Fig. 1 at 180 8C for 30 min. Finally, polished pallet was electroded by silver, and electrically polarized under the electric field of 3 kV mm 1. Microstructure was viewed by scanning electron microscopy (SEM, HITACHI model S-450). The magnetoelectric voltage coefficient (dE /dH ) was determined by measuring the electric field generated
Sample number
Thickness ratio of layers tPZT/tterfenol-D/tPZT
Total thickness
1# 2# 3# 4# 5#
3:1:3 1.25:1:1.25 0.667:1:0.667 0.375:1:0.375 0.2:1:0.2
2 mm
across the sample when a dc magnetic field and an ac bias were applied to it.
3. Results and discussion Five kinds of PZT/Terfenol-D/PVDF laminate composites as the nominal components shown in Table 1
Fig. 2. Typical microstructure of sample 1# (a) Panorama (b) PZT/PVDF (c) Terfenol-D/PVDF.
N. Cai et al. / Materials Science and Engineering B99 (2003) 211 /213
213
Fig. 3. The parameter dE /dH as function of frequency with different assembly.
have been prepared successfully through above-mentioned technology. Fig. 2 illustrates the typical microstructure of sample 1#. It can be seen that two layers of PZT/PVDF are compact (as shown in Fig. 2(a) and (b)), and Terfenol-D layer is porous (as shown in Fig. 2(b)). This inhomogeneous may be the result of the Terfenol-D particles were pulled out when fracturing or time and temperature of heat-pressing process which can be ameliorated by enlarging time and increasing temperature. Fig. 2(c) indicates that the Terfenol-D gain size is in a long range and most bigger than PZT. The variation of the dE /dH as a function of frequency from 50 Hz to 110 KHz for five different samples in 0.2 T magnetic field is illustrated in Fig. 3. With the increase of frequency, dE /dH varies moderately before 10 KHz, and then goes up abruptly. The result is accordance with the work of Bracbe [7]. This is due to the properties of the circuit with two capacitances (PZT and PVDF layers) and an inductance (Terfenol-D and PVDF layer) which must lead to a resonance which frequency can be obtained by calculation, and so cause to a maximum in certain frequency. So the five samples have the maximal value at the different frequency. In addition, the sample 4# has got the largest dE /dH value of 126.84 mV/cm.Oe at 107 kHz, which is mainly dependent on the piezoelectric constant d33. Fig. 4 reveals the relations of dE /dH and dc magnetic field in the frequency of 10 kHz. Magnetoelectric voltage coefficient dE /dH rapidly increase with the dc magnetic field in the range of 0 /0.1T , and saturated after 0.1T for sample 1, 2 and 3. This may be the result that the terfenol-D has been close to the saturated
Fig. 4. The parameter dE /dH as function of applied dc magnetic with different assembly.
distortion and PZT has powerful polarization in magnetic field of 0.1T (detailed in [1] Fig. 4). For the second sample, dE /dH has an apex value, and then decrease. Its mechanism is not clear, and need the further investigation.
4. Conclusion Magnetoelectric laminate composites of lead zirconate titanate (PZT), Tb0.28Dy0.72Fe1.95 (Terfenol-D) and poly vinylidene fluoride (PVDF) have been fabricated by heat pressing. The highest magnetoelectric coefficient (dE /dH) at 107 kHz is 126.84 mV/cm.Oe of laminate composite with thickness ratio of 0.375 (PZT/PVDF):1 (Terfenol-D/PVDF): 0.375 (PZT/PVDF).
References [1] C.W. Nan, Phys. Rev. B 50 (1994) 6082 /6088. [2] A.J. Freman, H. Schmid, Gordon and Breach, Magnetoelectric Interaction Phenomena in Crystals, London, 1975. [3] A.H. Nicola, J. Phys. Chem. B 104 (2000) 6694 /6709. [4] V.J. Folen, G.T. Rado, E.W. Stalder, Phys. Rev. Lett. 6 (1961) 607 /608. [5] G.T. Rado, V.J. Folen, Phys. Rev. Lett. 7 (1961) 310 /311. [6] E. Ascher, H. Rieder, H. Schmid, J. Appl. Phys. 37 (1966) 1404. [7] L.P.M. Bracbe, R.G. Van Vliet, Int. J. Electron. 5 (1981) 255 /262. [8] G. Srinivasan, E.T. Rasmussen, J. Gallegos, R. Sirnivasan, Phys. Rev. B 64 (2001) 214408. [9] J. Ryu, A. Va´zquez Carazo, K. Uchino, H.-E Kim, Jpn. J. Appl. Phys. 40 (2001) 4948 /4951.
The magnetoelectric properties of lead zirconate titanate/terfenol-D/ PVDF laminate composites Ning Cai, Junyi Zhai, Li Liu, Yuanhua Lin, Ce-Wen Nan * State Key Laboratory of New Ceramics and Fine Progressing, Department of Materials Science and Engineering, Tsinghua University, Beijing 100084, People’s Republic of China Received 14 June 2002; received in revised form 8 October 2002; accepted 21 October 2002
Abstract Lead zirconate titanate (PZT-5)/Tb0.28Dy0.72Fe1.95 (Terfenol-D)/poly vinylidene fluoride (PVDF) laminate composites were prepared using stacking and heat-pressing together one Terfenol-D/PVDF disk and two layers of PZT/PVDF. The dependence of the magnetoelectric conversion coefficient (dE /dH ) of these composites on the value of applied dc magnetic field, thickness of layers and frequency of the ac magnetic field has been studied systematically. The results indicate that the dE /dH can reach the maximum 126.84 mV/cm.Oe when the layers thickness ratio of PZT/PVDF to Terfenol-D/PVDF is 0.375/1.0. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Composite; Magnetoelectric effect; Laminate
1. Introduction Magnetoelectric effect (ME) is a coupled (or cross) two-field effect, in which the application of either a magnetic field or an electrical field induces an electric polarization as well as a magnetization [1]. In 1894 Pierre Curie predicted it prophetically first on the basis of symmetry considerations [2]. The experimental search began in Russia in the 1950’s with the replacement of some of the d0 B cations in ferroelectric perovskite oxides by magnetic dn cations [3]. Until 1960 /1961, the linear ME effect was only experimentally observed in the antiferroelectric Cr2O3 crystal [4,5]. Nickel iodine boracite (Ni3B7O13I) was discovered to be ferromagnetic ferroelectric in 1966 [6]. This was followed by the synthesis of many more multiferroic boracite compounds. Such magnetoelectric composites are exploited as sensors, waveguides, modulators, swiches, phase inverter, rectifier, etc., and find substantial application in the radioelectronics and microwave electronics[7,8]. For example, magetoelectric materials will be useful in * Corresponding author. Tel./fax: /86-10-6277-3587. E-mail address: [email protected] (C.-W. Nan).
microwave devices and high power electric transmission systems, which can measure the electromagnetic leak signal generated from these devices accurately. In addition, a magnetoelectric sensor will be an alternative tool of the Hall sensor for magnetic field measurement[9]. Jungho RYU [6] etc. have reported the big ME coefficient 5.9V mV/cm.Oe, but the method they used is very complex and need long time. In this paper, a simple method is introduced to fabricate laminated composites of lead zirconate titanate (PZT)/ Tb0.28Dy0.72Fe1.95 (Terfenol-D)/poly vinylidene fluoride (PVDF), which can reduce the time of producing. And their properties have been investigated detailed.
2. Experimental procedure As magnetostrictive materials, high magnetostrictive property under a relative low magnetic field bias is preferred. In order to achieve the high value of magnetoelectric effect Tb0.28Dy0.72Fe1.95 (Terfenol-D, /50 mm) alloy was employed as the magnetostrictive phase in our composites. As for the piezoelectric phase, PZT was chosen to prepare the composites due to its high
0921-5107/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved. doi:10.1016/S0921-5107(02)00534-2
212
N. Cai et al. / Materials Science and Engineering B99 (2003) 211 /213 Table 1 The composition of different samples
Fig. 1. Schematic of samples’ structure.
piezoelectric constants. Additionally, PVDF is employed to bend these two components. PZT (57vol.%, powder size of /5 mm piezoelectric constant d33 is 330) and Terfenol-D (57 vol.%, powder size of /50 mm) were mixed with PVDF (43 vol.%, powder) separately, and than sample pallets were heatpressed to be size of f 15 /2 mm according to Fig. 1 at 180 8C for 30 min. Finally, polished pallet was electroded by silver, and electrically polarized under the electric field of 3 kV mm 1. Microstructure was viewed by scanning electron microscopy (SEM, HITACHI model S-450). The magnetoelectric voltage coefficient (dE /dH ) was determined by measuring the electric field generated
Sample number
Thickness ratio of layers tPZT/tterfenol-D/tPZT
Total thickness
1# 2# 3# 4# 5#
3:1:3 1.25:1:1.25 0.667:1:0.667 0.375:1:0.375 0.2:1:0.2
2 mm
across the sample when a dc magnetic field and an ac bias were applied to it.
3. Results and discussion Five kinds of PZT/Terfenol-D/PVDF laminate composites as the nominal components shown in Table 1
Fig. 2. Typical microstructure of sample 1# (a) Panorama (b) PZT/PVDF (c) Terfenol-D/PVDF.
N. Cai et al. / Materials Science and Engineering B99 (2003) 211 /213
213
Fig. 3. The parameter dE /dH as function of frequency with different assembly.
have been prepared successfully through above-mentioned technology. Fig. 2 illustrates the typical microstructure of sample 1#. It can be seen that two layers of PZT/PVDF are compact (as shown in Fig. 2(a) and (b)), and Terfenol-D layer is porous (as shown in Fig. 2(b)). This inhomogeneous may be the result of the Terfenol-D particles were pulled out when fracturing or time and temperature of heat-pressing process which can be ameliorated by enlarging time and increasing temperature. Fig. 2(c) indicates that the Terfenol-D gain size is in a long range and most bigger than PZT. The variation of the dE /dH as a function of frequency from 50 Hz to 110 KHz for five different samples in 0.2 T magnetic field is illustrated in Fig. 3. With the increase of frequency, dE /dH varies moderately before 10 KHz, and then goes up abruptly. The result is accordance with the work of Bracbe [7]. This is due to the properties of the circuit with two capacitances (PZT and PVDF layers) and an inductance (Terfenol-D and PVDF layer) which must lead to a resonance which frequency can be obtained by calculation, and so cause to a maximum in certain frequency. So the five samples have the maximal value at the different frequency. In addition, the sample 4# has got the largest dE /dH value of 126.84 mV/cm.Oe at 107 kHz, which is mainly dependent on the piezoelectric constant d33. Fig. 4 reveals the relations of dE /dH and dc magnetic field in the frequency of 10 kHz. Magnetoelectric voltage coefficient dE /dH rapidly increase with the dc magnetic field in the range of 0 /0.1T , and saturated after 0.1T for sample 1, 2 and 3. This may be the result that the terfenol-D has been close to the saturated
Fig. 4. The parameter dE /dH as function of applied dc magnetic with different assembly.
distortion and PZT has powerful polarization in magnetic field of 0.1T (detailed in [1] Fig. 4). For the second sample, dE /dH has an apex value, and then decrease. Its mechanism is not clear, and need the further investigation.
4. Conclusion Magnetoelectric laminate composites of lead zirconate titanate (PZT), Tb0.28Dy0.72Fe1.95 (Terfenol-D) and poly vinylidene fluoride (PVDF) have been fabricated by heat pressing. The highest magnetoelectric coefficient (dE /dH) at 107 kHz is 126.84 mV/cm.Oe of laminate composite with thickness ratio of 0.375 (PZT/PVDF):1 (Terfenol-D/PVDF): 0.375 (PZT/PVDF).
References [1] C.W. Nan, Phys. Rev. B 50 (1994) 6082 /6088. [2] A.J. Freman, H. Schmid, Gordon and Breach, Magnetoelectric Interaction Phenomena in Crystals, London, 1975. [3] A.H. Nicola, J. Phys. Chem. B 104 (2000) 6694 /6709. [4] V.J. Folen, G.T. Rado, E.W. Stalder, Phys. Rev. Lett. 6 (1961) 607 /608. [5] G.T. Rado, V.J. Folen, Phys. Rev. Lett. 7 (1961) 310 /311. [6] E. Ascher, H. Rieder, H. Schmid, J. Appl. Phys. 37 (1966) 1404. [7] L.P.M. Bracbe, R.G. Van Vliet, Int. J. Electron. 5 (1981) 255 /262. [8] G. Srinivasan, E.T. Rasmussen, J. Gallegos, R. Sirnivasan, Phys. Rev. B 64 (2001) 214408. [9] J. Ryu, A. Va´zquez Carazo, K. Uchino, H.-E Kim, Jpn. J. Appl. Phys. 40 (2001) 4948 /4951.