Using density functional theory calculations, we investigate the feasibility of using silver on the perovskite A-site in high-performance lead-free piezoelectrics. The calculations show that silver atoms are ferroelectrically active and can off-center by 0.5 Å. To induce Ag ferroelctric behavior absent in pure AgNbO3 we explore solid solutions of AgNbO3 with well-known simple perovskites PbTiO3...

The atomic-scale structural and electric parameters of the 90° domain-walls in tetragonal ferroelectrics are of technological importance for exploring the ferroelectric switching behaviors and various domain-wall-related novel functions. We have grown epitaxial PbTiO3/SrTiO3 multilayer films in which the electric dipoles at 90° domain-walls of ferroelectric PbTiO3 are characterized by means of ...

We determine the relative thermodynamic stability of competing homogeneously and inhomogeneously ordered ferroelectric phases of PbTiO3 using its free-energy landscape, obtained from constrained-polarization moleculardynamics simulations with a first-principles effective Hamiltonian and thermodynamic integration. While we find that the tetragonal structure is thermodynamically most stable at te...

The pyroelectric infrared (PIR) sensor with the lead-titanate (PbTiO3) thin film has been successfully fabricated. A RF planar magnetron sputter was used to deposit PbTiO3 thin film. A perovskite thin film can be obtained. From the properties measurement we can obtain the remanent polarization Pr = 20.8 μc/cm and coercive electric field Ec = 79.365 kV/cm. The pyroelectric coefficient of 1.09 × ...

The orientation dependence of electromechanical properties of relaxor based ferroelectric single crystals Pb(Zn1/3Nb2/3)O3-(6-7)%PbTiO3 and Pb(Mg1/3Nb2/3)O3-33%PbTiO3 has been calculated by coordinate transformation. Different from previous studies, the optimum cutting orientations have been predicted in terms of their piezoelectric responses in the corresponding crystal planes. The calculation...

Since lead titanate was ®rst grown in single-crystal form in the 1930s, several independent reports of its linear birefringence have been published. Whilst there is overall qualitative agreement on its behaviour with temperature, the absolute values show some degree of variation. At 298 K they range from ÿ0.009 to ÿ0.013, a relative spread of 40%, whilst at 673 K the discrepancy is even greater...

We present a systematic evaluation of the effects of polarization switchability on surface structure and stoichiometry in BaTiO3 and PbTiO3 ferroelectric oxides. We show that charge passivation, mostly by ionic surface reconstructions, is the driving force for the stability of the surfaces, which suggests that varying the substrate polarization offers a new mechanism for controlling surface rec...

Ferroelectric nanostructures are promising building blocks for advanced electromechanical devices. In this paper, we report a hydrothermal synthesis of PbTiO3 nanoring and nanoring-nanowire hybrid structures. Evolution of the nanoring structure was suggested to be caused by the self-directed assembly of PbTiO3 nanoparticles, where polarization of the ferroelectric nanoparticles might direct the...

A Study of thin films preparation faces many challenges due to the environmentally sensitivity that could initiate effect towards device performance. Requirement to fabricate the passive device like capacitor at such nanoscaled thickness is quite challenges that would initiate the effect on the device performance. Nowadays, capacitor not just only existed by conventional dielectric material, it...