Dielectric properties of A- and B-site doped BaTiO3(II):La- and Ga-doped solid solutions

Abstract

Extremely small amounts of codoping La and Ga on the A and B sites of BaTiO 3 , respectively, resulting in a solid solution of the type Ba 1−3x La 2x Ga 4x Ti 1−3x O 3 , have been investigated. The compounds have been prepared by conventional solid-state reaction. The x-ray diffraction ͑XRD͒ shows the presence of the tetragonal ͑P4/mmm͒ phase only. The XRD data have been analyzed using the FULLPROF Rietveld refinement package. The compositions have been characterized by dielectric spectroscopy between room temperature and 200°C. The resulting compounds ͑0 ഛ x ഛ 0.008͒ exhibit a remarkable decrease in Curie temperature as well as a significant enhancement in the dielectric constant.

Multiferroicity in Ba 0.97 La 0.03 Ti 1 − x Ni x O 3 (0.03 ⩽ x ⩽ 0.07) ceramics

“…The increase in dielectric constant in La and Ni doped samples with the increase of dopant concentration may be firstly due to the increase in density and secondly due to the non-homogeneous distribution of additives throughout the specimen. The increases in dielectric constant with doping content is also reported by Gulwade et al in La and Ga co-doped BTO [31] and Patrovic et al in La and Mn co-doped BaTiO 3 [32]. The dielectric constant and dielectric loss for doped samples decrease rapidly with frequency increasing and then reaches a constant value.…”

Fabrication of Micrometer-Scaled Hierarchical Tubular Structures of CuS Assembled by Nanoflake-built Microspheres Using an In Situ Formed Cu(I) Complex as a Self-Sacrificed Template

“…The coordination compound is cyclo-tri-µ-thioacetamide-tris(chlorocopper(i)) (Cu 3 (TAA) 3 Cl 3 ) from the literature; 32 since TAA has a strong ability to combine with transition metal ions, the hexagonal prism-shaped intermediate should be a complex from the coordination reaction between CuCl 2 and TAA. Because there is no standard XRD pattern of cyclo-tri-µ-thioacetamidetris(chloro-copper(i)) (Cu 3 (TAA) 3 Cl 3 ) in the JCPDS database, we used the Fullprof software package to index the atoms as was done in the literature 33 using the cell parameters of singlecrystal cyclo-tri-µ-thioacetamide-tris(chloro-copper(i)) 3 from the literature 32 (space group No. 161, a ) 19.76 Å, c ) 7.065 Å).…”

Effects of ZrO2 additions on the dielectric properties of CaCu3Ti4O12

“…8 Many other examples exist in the literature that demonstrate that doping is an effective means of improving the dielectric properties of perovskite materials. [9][10][11][12] The effects of doping on dielectric properties for CaCu 3 Ti 4 O 12 have not been widely investigated. Doping with 2% Mn was found to decrease the permittivity from r ϳ 10 000 down to little more than 100 over the temperature range of 4.2-300 K. 13 In prior work, the effects of an aliovalent dopant ͑Nb 5+ ͒ directly substituting for Ti was explored with two different compositions with the chemical formulas CaCu 3 Ti 3.992 Nb 0.008 O 12 and CaCu 3 Ti 3.984 Nb 0.016 O 12 .…”