Piezoelectric materials are widely used in the design of smart structures. It is thus of major technological interest to provide efficient modelings of such structures. In the case of thin piezoelectric plates, classical studies generally lead to two different models. These two models can be linked to the distinction between sensors and actuators. Here, we extend these results to the second ord...

Rigorous upper and lower bounds for the e€ective moduli are obtained for heterogeneous piezoelectric materials, by generalizing the Hashin±Shtrikman variational principle to the coupled problems of piezoelectricity. The key in obtaining these bounds is the choice of the ®eld variables used in the variational principles, i.e., the strain tensor and the electric displacement vector or the stress ...

Piezoelectricity is a unique property of materials that permits the conversion of mechanical stimuli into electrical and vice versa. On the basis of crystal symmetry considerations, pristine carbon nitride (C3N4) in its various forms is non-piezoelectric. Here we find clear evidence via piezoresponse force microscopy and quantum mechanical calculations that both atomically thin and layered grap...

Thermally-induced loss of piezoelectricity in ferroelectric Na0.5Bi0.5TiO3–BaTiO3 Report Title The loss of piezoelectricity in ferroelectric sodium bismuth titanate (NBT) in solid solution with barium titanate ((1? x)NBT?xBT) is studied by means of thermal depoling and Raman spectroscopy. In the range 0?x?13%, the highest thermal stability of the piezoelectric coefficients is found in x=13%, fo...

Tetragonal ferroelectric/ferroelectric BaTiO(3)/PbTiO(3) superlattice under uniaxial tensile stress along the c axis is investigated from first principles. We show that the calculated ideal tensile strength is 6.85 GPa and that the superlattice under the loading of uniaxial tensile stress becomes soft along the nonpolar axes. We also find that the appropriately applied uniaxial tensile stress c...

As a simple model for piezoelectricity we consider a gas of infinitely many non-interacting electrons subject to a slowly timedependent periodic potential. We show that in the adiabatic limit the macroscopic current is determined by the geometry of the Bloch bundle. As a consequence we obtain the King-Smith and Vanderbilt formula up to errors smaller than any power of the adiabatic parameter. v...