Preparation, Characterization, and Properties of Dy‐Doped Small‐Grained BaTiO₃ Ceramics

Abstract

The effects of Dy doping and sintering parameters on the properties of BaTiO3 ceramics were studied. The average grain size decreases with increasing Dy content and is controlled at ∼1.5 μ m by 0.8 at.% Dy. The Curie temperature change, associated with ≤1.2 at.% Dy, is <3°C. The dielectric constant is ∼2600 for specimens doped with 0.8 at.% Dy, calcined at 1200°C, and sintered at 1450°C. The dielectric constant variation with ambient temperature is much less than that of conventional BaTiO3 ceramics. Lattice constant c decreases with increasing Dy concentration whereas a increases slightly. The effects of grain size on dielectric constant, lattice parameters, and linear thermal expansion coefficient are more pronounced than the chemical effects of Dy doping in the ferroelectric state, whereas in the paraelectric state, these characteristics are almost independent of grain size as well as Dy concentration. The decrease in the frequency of occurrence of 90° twins with decreasing grain size implies that internal stress, which develops when BaTiO3 ceramics are cooled below Tc, strongly influences the effects of grain size.

Influence of core-shell structured grain on dielectric properties of cerium-modified barium titanate

“…Nb205 in that it decreased the axial ratio (c/a ratio) of the tetragonal phase. A similar reduction in tetragonality (c/a ratio) has been observed with rare earth metal oxide addition [2,14] to BaTiO3.…”

Relationships between the Texture and Structure of BaTiO3and Its Tetragonal → Cubic Transition Enthalpy

“…We have utilized the Clabaugh method (20) using BaCl 2 и 2H 2 O, TiCl 4 , and C 2 O 4 и 2H 2 O (Merck pro analysis) the discovery of its extremely high dielectric constant. It is well known that the small particle size of BaTiO 3 starting as starting materials.…”

Effects of dysprosium oxide addition in bismuth sodium titanate ceramics

“…Some La-doped PZT (or PLZT) compositions were found to produce ceramics with high density and good transparency which make them suitable for electro-optic applications [1]. For non-lead electroceramics, Yamaji et al [2] have investigated the effect of doping Dy 2 O 3 in BaTiO 3 and found that the average grain sizes of doped ceramics were smaller while the dielectric constants were greater than those of undoped BaTiO 3 over a wide range of temperature.…”