Investigation of mechanical and electrical properties of Li doped sodium niobate ceramic system
ABSTRACTThe Na0.96Li0.04NbO3 ceramic solid solution was prepared by means of a two-stage hot-pressing technology. The X-ray diffraction analysis showed the formation of a single perovskite phase with an orthorhombic symmetry in the investigated composition. The microstructure and EDS measurements were performed. They confirmed the high purity and the expected qualitative composition. A good homogeneity of the microstructures and a small degree of porosity were observed. The elastic modulus (the Young's modulus E, shear modulus G, and Poisson's ratio ν) of Na0.96Li0.04NbO3 were determined with the use of an ultrasonic method. The electrical properties of Na0.96Li0.04NbO3 ceramics were invest…
Ultrasonication as a Method of Investigation of the Mechanical Properties of Doped Hafnium Barium Titanate
The purpose of this study was to fabricate dense ceramic specimens from the system of BaTiO3-BaHfO3 and then to perform mechanical tests. The effect of Hf content on a microstructure and mechanical properties of the BaTiO3-BaHfO3 solid solution was investigated at room temperature. To determine the elastic constants (the Young′s modulus E, the shear modulus G, bulk modulus K and the Poisson′s ratio v) of BaHfxTi1-xO3 a method of measurement of the longitudinal (VL ) and transverse (VT ) ultrasonic wave velocities for this type of material was developed.
Composition-related structural, thermal and mechanical properties of Ba1−xSrxTiO3ceramics (0 ≤x≤ 0.4)
The Ba1−xSrxTiO3 (BST) ceramics were prepared by conventional ceramic method. The crystalline structure and morphology were studied by X-ray diffraction and scanning electron microscopy, respectively. Experimental results show that increase of sintering temperature leads to an uncontrolled precipitating of the phase with a lower content of Ti. The dielectric constant and specific heat as a function of composition and temperature were investigated. The increasing concentration of Sr ions leads to a shift of the Curie point below room temperature. To determine the elastic constants (the Young's modulus E, the shear modulus G and the Poisson's ratio v) of BST, a method of measurement of the lo…
The effects of the additive of Eu ions on elastic and electric properties of BaTiO3ceramics
ABSTRACTThe BaTiO3 and BaTiO3+X%wt.Eu2O3 (X = 1, 2, 3) ceramics were prepared by a solid phase reaction. The structural and morphology studies were carried out by means of an X-ray diffraction technique and scanning electron microscopy, respectively. Elastic moduli were determined with the use of an ultrasonic method. The dielectric permittivity (ϵ′) and tanδ as a function of composition and temperature were investigated. The increasing concentration of Eu ions leads to a slight shift of the Curie temperature and changes the characteristics of ϵ′ and tanδ. The structural, mechanical and dielectric properties of the BTEX ceramics were discussed in terms of microstructure and dopants contents.
Physical properties and microstructure characteristics of (1–x)BaTiO3–xCaTiO3 systems
The study investigates the microstructure, thermal and mechanical properties of (1–x)BaTiO3–xCaTiO3 ((1–x)BT–xCT)) (x = 0.01, 0.04, 0.08) samples. The BT–CT system to be tested was formed as a soli...
Physical Properties of Ba0.95Pb0.05TiO3+0.1%Co2O3
The single-phase perovskite structure of the Ba0.95Pb0.05TiO3+0.1%Co2O3 ceramics was confirmed by the X-ray diffraction method. Microstructural studies revealed that the samples were of good quality and chemically homogeneous. The thermal behaviour of ceramics was studied using the in situ high-temperature X-ray synchrotron powder diffraction investigation. The energy gap of about 3.2 eV was estimated using a reflectance spectroscopy. Measurements showed the influence of Pb and Co on the character of phase transition in the BaTiO3 structure. The results were compared to the ones obtained for pure BaTiO3.