A series of Pb<sub>1-x</sub>Ni<sub>x</sub>TiO<sub>3</sub> (x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared by the general ceramic and co-precipitation method. The grain size decrea...A series of Pb<sub>1-x</sub>Ni<sub>x</sub>TiO<sub>3</sub> (x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared by the general ceramic and co-precipitation method. The grain size decreased with increasing Ni contents. The piezoelectric modulus d33 increased with increasing Ni contents. It was observed also the d<sub>33</sub> of the nanocomposite Pb<sub>1-x</sub>Ni<sub>x</sub>TiO<sub>3</sub> prepared by co-precipitation method is higher than those of the prepared by general ceramic method. The coupling factor k<sub>p</sub> increased by the more doping of Ni. The ultrasonic wave velocity decreased also with increasing Ni contents. The polarized nano-sample of composition Pb<sub>0.5</sub>Ni<sub>0.5</sub>TiO<sub>3</sub> is suitable for improving application of useful piezoelectric technology.展开更多
A series of perovskite type oxides with formula La1-xHoxFeO3, with Ho substitute for La, where (x = 0.1, 0.2, 0.3 and 0.4). The samples have been prepared by the standard ceramic technique, sintered at 1200˚C...A series of perovskite type oxides with formula La1-xHoxFeO3, with Ho substitute for La, where (x = 0.1, 0.2, 0.3 and 0.4). The samples have been prepared by the standard ceramic technique, sintered at 1200˚C for nine hours. Their crystalline structure was investigated using X-ray diffraction and IR spectroscopy. The X-ray diffraction analysis illustrates that the system La1-xHoxFeO3 has a perovskite orthorhombic phase. IR absorption spectra of La1-xHoxFeO3 showed two main characteristic absorption bands in the far infrared region. These bands are assigned to oxygen octahedral bending vibration and oxygen tetrahedron stretching vibration. It was found that the DC electrical conductivity increases linearly with temperature ensuring the semiconducting nature of the samples. The dielectric properties, Electron Spin Resonance (ESR) spectra, and thermal properties have been studied, to go through the material and explore its ability to be used for many industrial applications.展开更多
The pure spinel phase of Ni0.45Co0.2Zn0.35F2O4[NCZF] was prepared by co-precipitation method. The nanocomposite [(NCZF)1-x(Na(ac.ac))x] (x = 0%, 20%, 40%, 60%, 80%, 100%) was prepared by mixing two phases: ferrite pha...The pure spinel phase of Ni0.45Co0.2Zn0.35F2O4[NCZF] was prepared by co-precipitation method. The nanocomposite [(NCZF)1-x(Na(ac.ac))x] (x = 0%, 20%, 40%, 60%, 80%, 100%) was prepared by mixing two phases: ferrite phase and ferroelectric phase. The magnetic characters of compo-sites performed using vibrating sample magnitude (VSM) at room temper-ature with maximum applied field up to 2 kG. For smaller particle size 30.89 nm. The saturation magnetization Ms decreases linearly with increasing particle size. The effect of temperature on the electrical resistivity of the different composites samples was studied. It is noted that, the resistivity decreases with rising temperature to have a minimum value at ferroelectric transition temperature, above this value the resistivity increases. The dielectric constant increases with increasing temperature for all composites. The dielectric loss tan (δ) as a function of temperature sharply with temperature reached to maximum value at ferroelectric phase transition then decrease again.展开更多
文摘A series of Pb<sub>1-x</sub>Ni<sub>x</sub>TiO<sub>3</sub> (x = 0, 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared by the general ceramic and co-precipitation method. The grain size decreased with increasing Ni contents. The piezoelectric modulus d33 increased with increasing Ni contents. It was observed also the d<sub>33</sub> of the nanocomposite Pb<sub>1-x</sub>Ni<sub>x</sub>TiO<sub>3</sub> prepared by co-precipitation method is higher than those of the prepared by general ceramic method. The coupling factor k<sub>p</sub> increased by the more doping of Ni. The ultrasonic wave velocity decreased also with increasing Ni contents. The polarized nano-sample of composition Pb<sub>0.5</sub>Ni<sub>0.5</sub>TiO<sub>3</sub> is suitable for improving application of useful piezoelectric technology.
文摘A series of perovskite type oxides with formula La1-xHoxFeO3, with Ho substitute for La, where (x = 0.1, 0.2, 0.3 and 0.4). The samples have been prepared by the standard ceramic technique, sintered at 1200˚C for nine hours. Their crystalline structure was investigated using X-ray diffraction and IR spectroscopy. The X-ray diffraction analysis illustrates that the system La1-xHoxFeO3 has a perovskite orthorhombic phase. IR absorption spectra of La1-xHoxFeO3 showed two main characteristic absorption bands in the far infrared region. These bands are assigned to oxygen octahedral bending vibration and oxygen tetrahedron stretching vibration. It was found that the DC electrical conductivity increases linearly with temperature ensuring the semiconducting nature of the samples. The dielectric properties, Electron Spin Resonance (ESR) spectra, and thermal properties have been studied, to go through the material and explore its ability to be used for many industrial applications.
文摘The pure spinel phase of Ni0.45Co0.2Zn0.35F2O4[NCZF] was prepared by co-precipitation method. The nanocomposite [(NCZF)1-x(Na(ac.ac))x] (x = 0%, 20%, 40%, 60%, 80%, 100%) was prepared by mixing two phases: ferrite phase and ferroelectric phase. The magnetic characters of compo-sites performed using vibrating sample magnitude (VSM) at room temper-ature with maximum applied field up to 2 kG. For smaller particle size 30.89 nm. The saturation magnetization Ms decreases linearly with increasing particle size. The effect of temperature on the electrical resistivity of the different composites samples was studied. It is noted that, the resistivity decreases with rising temperature to have a minimum value at ferroelectric transition temperature, above this value the resistivity increases. The dielectric constant increases with increasing temperature for all composites. The dielectric loss tan (δ) as a function of temperature sharply with temperature reached to maximum value at ferroelectric phase transition then decrease again.
