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A grand challenge with regard to multilayer ceramic capacitor (MLCC) technology is to simultaneously increase permittivity, material break-down strength and resistivity, while reducing material dissipation loss, and temperature sensitivity of permittivity, using reasonably environmentally friendly constituents. Dipole-like substituted barium titanate (BaTiO3), Ba[(M1/20Ta1/20)Ti9/10]O3 where M is a trivalent ion, Sc3+, Cr3+, Mn3+, or Fe3+, and more complicated electric-field interaction materials, Ba[(M1/30Ta2/30)Ti9/10]O3 where M is a divalent ion, Mn2+, Ni2+, or Cu2+, are investigated as potential candidate materials for MLCC technology. Measured temperature dependent, 273 K to 1173 K, electrical conductivity of Ba[(M1/20Ta1/20) Ti9/10]O3 and Ba[(M1/30Ta2/30)Ti9/10]O3 are reported. The dipole-like substituted materials, Ba[(M1/20Ta1/20)Ti9/10]O3, possess activation energies ranging from 2.02 to 2.40 eV and are nearly independent of the M3+ ion utilized. More complicated electric-field interaction materials, Ba[(M1/30Ta2/30)Ti9/10]O3 possess activation energies ranging from 2.50 to 2.61 eV and are nearly independent of the M2+ ion utilized. The results suggest that the introduction of stronger dipole-like electric fields increase the activation energy of the matrix compared to BaTiO3. Hence, dipole-like substituted materials, Ba[(M1/20Ta1/20)Ti9/10] O3, and more complicated electric-field interaction materials, Ba[(M1/30Ta2/30) Ti9/10] O3, which can be used to significantly and controllable tailor the activation energy of BaTiO3 based materials, remain of interest for MLLC technology. [ABSTRACT FROM AUTHOR]

Spectroscopic, structural and electrical properties of Ba[(Ho,Sb)0.05Ti0.9]O3 have been characterized to determine the effects of charge compensated dipole-like (Ho3+, Sb5+) substitutions on temperature dependent material properties. XRD and Rietveld analysis have been used to determine lattice parameters and coefficients of thermal expansion from RT to 1373 K. Capacitance measurements have been conducted over the temperature range [198 K, 1073 K] and frequency range [10 Hz, 1 MHz] to investigate the dielectric properties, including Curie temperature. The microstructural features of the material, observed using a scanning electron microscope, show submicron grain size. The oxidation states of Ho3+ and Sb5+ substitutions within Ba[(Ho,Sb)0.05Ti0.9]O3 have also been indirectly investigated using X-ray photoelectron spectroscopy and are reported in relation to the observed Ti 2p spectrum. Ba[(Ho,Sb)0.05Ti0.9]O3 has a maximum relative permittivity of about 5000 at 267 K that corresponds to an orthorhombic () to tetragonal (P4/mmm) phase transition. Another structural phase transition of Ba(Ho0.05Sb0.05Ti0.9)O3, from tetragonal (P4/mmm) to cubic (), is observed between 623 K and 673 K through a peak in the dielectric constant as well as Rietveld refinement of XRD data. Thus, charge compensated dipole-like (Ho3+, Sb5+) substitutions within BaTiO3 result in the formation of a solid solution as observed through the material Ba[(Ho3+,Sb5+)0.05Ti0.9]O3. Compared with BaTiO3, the material possesses some similar properties, like the same structural sequence with increasing temperature, yet other properties, like diffuseness of the temperature dependent relative permittivity, are fundamentally different and consistent with a dipole-like glass state. Experimental results are compared with several currently utilized models in an effort to better understand the effect that dipole-like substitutions have on material properties. [ABSTRACT FROM AUTHOR]

Spectroscopic, structural and electrical properties of Ba[(Ho,Sb)0.05Ti0.9]O3 have been characterized to determine the effects of charge compensated dipole-like (Ho3+, Sb5+) substitutions on temperature dependent material properties. XRD and Rietveld analysis have been used to determine lattice parameters and coefficients of thermal expansion from RT to 1373 K. Capacitance measurements have been conducted over the temperature range [198 K, 1073 K] and frequency range [10 Hz, 1 MHz] to investigate the dielectric properties, including Curie temperature. The microstructural features of the material, observed using a scanning electron microscope, show submicron grain size. The oxidation states of Ho3+ and Sb5+ substitutions within Ba[(Ho,Sb)0.05Ti0.9]O3 have also been indirectly investigated using X-ray photoelectron spectroscopy and are reported in relation to the observed Ti 2p spectrum. Ba[(Ho,Sb)0.05Ti0.9]O3 has a maximum relative permittivity of about 5000 at 267 K that corresponds to an orthorhombic () to tetragonal (P4/mmm) phase transition. Another structural phase transition of Ba(Ho0.05Sb0.05Ti0.9)O3, from tetragonal (P4/mmm) to cubic (), is observed between 623 K and 673 K through a peak in the dielectric constant as well as Rietveld refinement of XRD data. Thus, charge compensated dipole-like (Ho3+, Sb5+) substitutions within BaTiO3 result in the formation of a solid solution as observed through the material Ba[(Ho3+,Sb5+)0.05Ti0.9]O3. Compared with BaTiO3, the material possesses some similar properties, like the same structural sequence with increasing temperature, yet other properties, like diffuseness of the temperature dependent relative permittivity, are fundamentally different and consistent with a dipole-like glass state. Experimental results are compared with several currently utilized models in an effort to better understand the effect that dipole-like substitutions have on material properties. [ABSTRACT FROM AUTHOR]