Origin of Piezoelectricity in an α-Quartz

Abstract

In this study, a novel approach was proposed to improve the characterization of HfO 2 . Fluorine was incorporated by CF 4 plasma to improve the HfO 2 gate dielectric properties including leakage current, breakdown voltage and hysteresis. The hysteresis of capacitance-voltage characteristics can be reduced to approximately 10% hysteresis voltage for the samples with CF 4 plasma treatment. An inner-interface trapping model is presented to explain the hysteresis. The secondary-ion mass spectroscopy (SIMS) results show that there is a significant incorporation of fluorine (F) at the interface between the HfO 2 thin film and silicon substrate. The incorporation of F effectively suppressed leakage current and improved carrier trapping without an increase in interfacial layer thickness.

α-β Transition in Quartz: Temperature and Pressure Dependence of the Thermodynamic Quantities for β-Quartz and β-Cristobalite as Piezoelectric Materials

“…Dawson [6] showed experimentally that the piezoelectric effect increased by 20 % from room temperature to 60°C, which decreased to zero at about 573°C. Concerning the origin of piezoelectricity, particularly, in an a-quartz, it has been stated [20] that the distortion of the unit tetrahedron gives rise to an electric polarization along the electric axis in the unit, which induces the piezoelectric effect in the quartz crystal. Thus, when the pressure is applied to quartz crystal, piezoelectric polarization is produced.…”

“…Thus, when the pressure is applied to quartz crystal, piezoelectric polarization is produced. So, the piezoelectric polarization is considered as the sum of unit polarization since the balance of the polarizations is destroyed in a lattice structure when it is deformed by stress [20]. The piezoelectric effect in an a-quartz has been studied previously using a microscopic rigid stick-bar model [20].…”

Understanding the Role of Helical Chains in the Formation of Noncentrosymmetric Solids

“…For instance, the designed synthesis of noncentrosymmetric solids is a challenging problem for the future fabrication of materials with ferroelectric, pyro- and piezoelectric, and other nonlinear optical (NLO) properties SiO 2 (quartz), Cu(pyridine) 4 Cr 2 O 7 , and others. − However, an equally large group of materials that contain helical chains do have inversion centers. In general, how to design or make a noncentrosymmetric solid from inorganic helices relies on our understanding of ligand effects and crystal packing.…”

Origin of Life in the Water of the Earth

“…When liquid oil is dropped into liquid water, the hydrophobic hydrocarbon molecules gather on the surface of the water to form an oil film. Water molecules become organized in a "spiral structure (α-quartz lattice structure [5] 1974.) under the influence of the oil film.…”