Study of Dielectric Relaxation Behavior of Co-doped BCZT Ceramics

doi:10.3724/SP.J.1077.2013.12271

Abstract

Abstract:

Ba_0.9175Ca_0.08Nd_0.0025(Zr_0.18Ti_0.8175-_xY_xMn_0.0025)O₃(BCZT-Y, x=0, 0.5mol%, 0.75mol%, 1.0mol%, 1.5mol%, 2.0mol%) ferroelectric ceramics was prepared by a solid phase reaction. The influence of Y³⁺doping on the structure and dielectric properties of BCZT-Y ceramics was investigated. Results showed that with the Y³⁺contents increasing, Y³⁺ion substitution can be almost incorporated into the Ti⁴⁺ site, and the density of BCZT-Y ceramics increased from 4.029 g/cm³to 6.058 g/cm³. The Curie temperature was shifted to lower temperature, and the ε_r-T peak was decreased and broaden. The ferroelectric relaxor characteristics were obtained while Y³⁺ ion content was further increased, which were consistent with the Lorenz-type formula fitting. It was found that the area of ferroelectric hysteresis loop became narrow and slant, the remnant polarization (P_r) and coercive field (E_c) reduced with the increase of Y³⁺content.

Key words: co-doped, dielectric properties, relaxor ferroelectrics, hysteresis loop

CLC Number:

TM22

XU Qin, DING Shi-Hua, SONG Tian-Xiu, PENG Yong, WU Xiao-Liang. Study of Dielectric Relaxation Behavior of Co-doped BCZT Ceramics[J]. Journal of Inorganic Materials, 2013, 28(4): 441-446.

Figures/Tables 8

Fig. 1 XRD patterns of the samples doped with different contents of Y3+

Table 1 Density for BCZT-Y ceramics with different contents of Y3+

x /mol%	0.5	0.75	1.0	1.5	2.0
ρ/ (g•cm^-3)	4.029	5.532	5.712	5.794	6.058

Fig. 2 Temperature dependence of dielectric constant for Ba0.92Ca0.08(Ti0.82Zr0.18)O3 based ceramics at different frequencies

Fig. 3 Temperature dependence of dielectric constant and dielectric loss (tanδ) for BCZT-Y ceramics with different contents of Y3+ at 1 kHz.

Table 2 Remnant polarization Pr and coercive field Ec for variation contents BCZT-Y ceramics (-20℃)

Sample	P_r/(μC·cm^-2)	E_c/(kV·m^-1)
x =0	8.6320	1.0833
x =0.5mol%	3.8688	0.7440
x =0.75mol%	3.1314	0.6173
x =1.5mol%	0.7720	0.3750
x =2.0mol%	0.4825	0.3840

Fig. 4 Temperature T dependence fitting figures of dielectric constant of BCZT-Y ceramics with different contents of Y3+ at 1 kHz

Table 3 Temperature T dependence fitting results of dielectric constant of BCZT-Y ceramics with different contents of Y3+ at 1 kHz

x/mol%	f/kHz	T_m/℃		T_A/℃				/℃
x/mol%	f/kHz	T_m/℃		T<T_m	T>T_m	T<T_m	T>T_m	T<T_m	T>T_m
0	1	32	17507	29.405	31.233	16719	16875	12.391	11.053
0.25	1	18	15837	13.439	19.736	16214	15507	33.827	12.728
0.50	1	6	17008	2.4986	7.1031	17078	16779	35.533	14.098
0.75	1	6	13753	7.4316	8.0211	13881	13719	38.016	27.828
1.00	1	-1	12543	7.6582	2.6639	12935	12516	41.562	36.613
1.50	1	-10	11658	-8.9058	-9.0245	11681	11526	53.724	47.052

Fig. 5 Polarization-electric field(P-E) hysteresis loops of BCZT-Y ceramics with different contents of Y3+ at -20℃

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