Structural and dielectric properties of Y₂O₃-doped Ba_0.92Sr_0.08Ti_0.95Sn_0.05O₃ ceramics

Abstract

The structural and dielectric properties of Ba_0.92Sr_0.08Ti_0.95Sn_0.05O₃(BSTS)+x(molar ratio, %)Y³⁺ ceramics are investigated. Combining the lattice parameters and the distortion of crystal lattice, an alternation of substitution preference of Y³⁺ ion for the host cations in perovskite lattice is found. Owing to Y³⁺ ion entering the A site, the maximum dielectric constant is 5 627 for 1.25% Y³⁺-doped samples; when Y³⁺ ion is more than 1.25%, it tends to occupy the B site in perovskite lattice, causing a drop in the dielectric constant. Owing to the appearance of oxygen vacancy, the optimized dielectric loss is 0.004 for 1.25% Y³⁺-doped samples. The thermal stability of BSTS ceramics is significantly improved and the Curie temperature shifts to lower value with the amount of Y₂O₃ increased, making it a superior candidate for capacitor applications.

Keywords

dielectric ceramics / Y³⁺-doping / microstructure / dielectric properties

References

[1] Wu L., Cheny C. Direct-current field dependence of dielectric properties in alumina-doped barium strontium titanate[J] J Am Ceram Soc, 2000, 83(7): 1713-1719.

[2] Herner S. B., Selmi F. A., Varadan V. V., et al. The effect of various dopants on the dielectric properties of barium strontium titanate[J]. Mater Lett, 1993, 15(5): 317-324.

[3] Potrepka D. M., Tidrow S. C., Tauber A. Improved temperature stability of microwave properties in tunable devices using substituted Ba_1−xSr_xTiO₃[J]. Integr Ferroelectr, 2002, 42(1): 97-121.

[4] Zhang C., Qu Y. F., Ma S. C. Dielectric properties of Sb₂O₃-doped Ba_0.672Sr_0.32Y_0.008TiO₃[J]. Mater Lett, 2007, 61(5): 1007-1010.

[5] Zhang C., Qu Y. F., Ma S. C. Structural and dielectric properties of Sb₂O₃-doped(Ba_0.992−xSr_xY_0.008)TiO_3.004 ceramics[J]. Mater Sci Eng B, 2007, 136(2): 118-122.

[6] Liang R. H., Dong X. L., Chen Y. Effect of various dopants on the tunable and dielectric properties of Ba_0.6Sr_0.4TiO₃ ceramics[J]. Ceram Int, 2005, 31(8): 1097-1101.

[7] Narang S. B., Kaur D., Bahel S. Dielectric properties of lanthanum substituted barium titanate microwave ceramics[J]. Mater Lett, 2006, 60(26): 3179-3182.

[8] Wang X., Qu Y., Li X., et al. Effect of La₂O₃ dopant on the structure and dielectric properties of Ba_0.92Sr_0.08Ti_0.9Sn_0.1O₃ ceramics[J]. Piezoelectrics and Acoustooptics, 2009, 31(4): 556-558.

[9] Garcia S., Font R., Portelles J., et al. Effect of Nb doping on (Sr, Ba) TiO₃ ceramic samples[J]. J Electroceram, 2001, 6(1): 101-108.

[10] Zhou Z. H., Du P., Wen W., et al. Dielectric properties of 0.7BaO-0.3SrO-(1-y)TiO₂-yNb₂O₅ composite ceramics[J]. Mater Chem Phys, 2004, 87(3): 430-434.

[11] Chen R. Z., Wang X. H., Li L. T. Effects of Nb/Co ratio on the dielectric properties of BaTiO₃-based X7R ceramics[J]. Mater Sci Eng B, 2003, 99(2): 298-301.

[12] Kowalski K., Ijjaali M., Bak T. Electrical properties of Nb-doped BaTiO₃[J]. J Phy Chem Solids, 2001, 62(3): 543-551.

[13] Brzozowski E., Castro M. S. Grain growth control in Nb-doped BaTiO₃[J]. J Mater Process Tech, 2005, 168(3): 464-470.

[14] Wang S., Zhang S. R., Zhou X. H. Investigation on dielectric properties of BaTiO₃ co-doped with Ni and Nb[J]. Mater Lett, 2006, 60(7): 909-911.

[15] Varatharajan R., Madeswaran S., Jayavel R. N. BST: Crystal growth and ferroelectric properties[J]. J Cryst Growth, 2001, 225(2/3/4): 484-488.

[16] Stojanovic B. D., Foschini C. R., Zaghete M. A. Size effect on structure and dielectric properties of Nb-doped barium titanate[J]. J Mater Process Tech, 2003, 143–144 802-806.

[17] Hao S. E., Sun L., Huang J. X. Preparation and dielectric properties of Dy, Er-doped BaZr_0.2Ti_0.8O₃ ceramics[J]. Mater Chem Phys, 2008, 109(1): 45-49.

[18] Kim J. H., Yoon S. H. Effects of Y₂O₃ addition on electrical conductivity and dielectric properties of Ba-excess Ba-TiO₃[J]. J Eur Ceram Soc, 2007, 27(2/3): 1113-1116.

[19] Wang X., Qu Y., Jin Lili. Influence of doping Y₂O₃ on dielectric properties of Ba_0.92Sr_0.08Ti_0.9Sn_0.1O₃ ceramics[J]. Piezoelectrics and Acoustooptics, 2008, 30(6): 738-740.

[20] Song S. N., Gao L. N., Zhai J. W., et al. Crystal orientation dependence of the inplane dielectric properties for Ba(Sn, Ti)O₃ thin films[J]. Appl Surf Sci, 2008, 254(16): 5120-5123.

[21] Song S. N., Gao L. N., Zhai J. W., et al. Effects of substrates on the structure and dielectric properties of Ba(Sn_0.15Ti_0.85)O₃ thin films[J]. Appl Surf Sci, 2008, 254(15): 4439-4443.

[22] Buscaglia M. T., Buscaglia V., Viviani M., et al. Influence of foreign ions on the crystal structure of BaTiO₃[J]. J Eur Ceram Soc, 2000, 20(12): 1997-2007.

[23] Watanabe K., Ohsato H., Kishi H., et al. Solubility of La-Mg and La-Al in BaTiO₃[J]. Solid State Ion, 1998, 108(1–4): 129-135.

[24] Dean J. A. Langes Handbook of Chemistry[M]. 2003, Beijing, China: Science Press.

[25] Hou Y. D., Zhu M. K., Gao F., et al. Effect of MnO₂ addition on the structure and electrical properties of Pb(Zn_1/3-Nb_2/3)_0.20(Zr_0.50Ti_0.50)_0.80O₃ ceramics[J]. J Am Ceram Soc, 2004, 87(5): 847-850.

[26] Li W., Qi J. Q., Wang Y. L., et al. Doping behaviors of Nb₂O₅ and Co₂O₃ in temperature stable BaTiO₃-based ceramics[J]. Mater Lett, 2002, 57(1): 1-5.

[27] Kim D. W., Ko K. H., Kwon D. K., et al. Origin of microwave dielectric loss in ZnNb₂O₆-TiO₂[J]. J Am Ceram Soc, 2002, 85(5): 1169-1172.