Improved dielectric breakdown strength of Dy doped (Ba_0.97Ca_0.03)(Ti_0.98Mg_0.02)O₃ ceramics with nanosized grains

Abstract

Phone: þ86 21 5241 1042, Fax: þ86 21 5241 3122 The (Ba 0.97Àx Ca 0.03 Dy x )(Ti 0.98 Mg 0.02 )O 3 (BCTDM-nano) (x ¼ 0, 0.005, 0.01, 0.02, 0.03) ceramics with nanosized grains were synthesized through a solid-state reaction method. The influence of Dy 3þ substitution on the lattice and electrical properties were investigated. The X-ray diffraction and Raman scattering analyses demonstrate that the Dy 3þ ions could modulate the doping position of Ca 2þ and Mg 2þ and affect the tetragonality and defects in BaTiO 3 matrix. The maximum dielectric constant was increased up to 2500 for the sample with x ¼ 0.01. A high dielectric breakdown strength of 239 kV cm À1 was obtained at x ¼ 0.01. The high grain boundary resistance resulted from a charge compensation by Dy doping benefits the improved dielectric breakdown strength. Original Paper 1700149 (3 of 6) Z. Yang et al.: Dy doped (Ba 0.97 Ca 0.03 )(Ti 0.98 Mg 0.02 )O 3 ceramics Original Paper 1700149 (5 of 6) Z. Yang et al.: Dy doped (Ba 0.97 Ca 0.03 )(Ti 0.98 Mg 0.02 )O 3 ceramics

Core–rim structure evolution and electric properties of Ca–Mg–Dy-co-doped BaTiO3 ceramics

“…2a) show the typical morphology of BT4 ceramics. Similar to the samples prepared by the conventional method, 19,20 the core–rim structured grains can be frequently observed. The size of the core is about 250 ± 40 nm, almost equal to the size of the raw BaTiO 3 powders (## 215 ± 49 nm, Fig.…”

“…37 Dy 3+ also prefers to occupy the Ba site to form Dy Ba owing to the presence of the Mg 00 Ti acceptor. 19 3.6 Multi-scale microstructure evolution mechanism and microstructure-property relationship…”

“…16 This effect was further enhanced by co-doping with other elements. [17][18][19] Yang et al and Gu et al reported 95BaTiO 3 -2MgO-2CaCO 3 -1Dy 2 O 3 ceramics with their improved breakdown strength, flattened e 0 -T characteristics, and excellent reliability. 18,19 Chen et al found that about 25% of the grains possessed core-rim structure in Ca, Mg, and Dy co-doped BaTiO 3 ceramics, which could delay the migration of V O and prolong the lifetime of MLCCs.…”

“…[17][18][19] Yang et al and Gu et al reported 95BaTiO 3 -2MgO-2CaCO 3 -1Dy 2 O 3 ceramics with their improved breakdown strength, flattened e 0 -T characteristics, and excellent reliability. 18,19 Chen et al found that about 25% of the grains possessed core-rim structure in Ca, Mg, and Dy co-doped BaTiO 3 ceramics, which could delay the migration of V O and prolong the lifetime of MLCCs. 20 Just because of its critical role in the development of BaTiO 3 -based MLCC dielectrics, the precise control of the core-rim structure during the material preparation appears especially important, for which the understanding of the formation and evolution mechanism of core-rim structure in sintering should be promoted.…”