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Miniaturized Whispering Gallery Mode (WGM) temperature sensor has great potentials of high resolution and great on-chip integration capability. This study focuses on the development of this kind of sensor based on the shifting wavelength of the optical resonance due to thermal expansion and thermo-optic effects of a silica microsphere. Excellent linear(More)
Structural health monitoring (SHM) is an emerging field in which smart materials interrogate structural components to predict failure, expedite needed repairs, and thus increase the useful life of those components. Piezoelectric wafer active sensors (PWAS) have been previously adhesively-bonded to structures and demonstrate the ability to detect and locate(More)
The ferroelectric and strain behavior of the Ba(Ti12yCey)O3 solid solutions was studied. Three phase transition temperatures were shifted with increasing Ce concentration, and pinched at y 50.06. The samples could be structurally indexed by x-ray diffraction in a tetragonal symmetry at y<0.06; and in a pseudo-cubic symmetry at y.0.06. The strain levels in(More)
The field distribution, dielectric constant, and loss in a two-phase composite, in which phase A is distributed inside a square matrix of phase B, have been calculated using the finite-element method ~FEM!. The calculation was carried out by taking into account different shapes for phase A, such as circles, triangles, and rings with different sizes. The(More)
The dielectric behavior of SrTiO3 single crystals under high dc electric field ~up to 50 kV/cm! is reported in this letter. The rounded dielectric constant peaks are induced by the application of dc bias, and the corresponding dielectric losses are observed. The results show that dielectric loss under dc bias consists of several components coming from(More)
The effect of dc electric field and post-treatment on the dielectric properties of SrTiO3 single crystals are reported. Both the dielectric constant and the loss tan d decrease after post-treatment in flowing oxygen environment for 26 h at 1100 °C. The possible physical mechanism is briefly discussed. The dielectric behavior under dc electric field is(More)
The doping effect on the structural, microstructural and dielectric properties of bismuth layer structured SrBi<sub>2</sub>Nb<sub>2</sub>O<sub>9</sub>(SBN) ferroelectric ceramics has been investigated. The samples were obtained from the solid state reaction sintering method. Particularly, the A-site cation substitution of Sr<sup>2+</sup> by La<sup>3+</sup>(More)
The dielectric and conduction behavior of SrTiO3 thin films deposited on a SrTiO3 single-crystal substrate is studied. Without dc bias, an obvious dielectric ‘‘defect mode’’ in the dielectric loss is observed in the temperature range of ;100–200 K; however, no noticeable corresponding dielectric constant peak is observed. By applying a high dc bias ~>40(More)
This article reports a study on the dielectric relaxation processes of Cd2Nb2O7 compound. Three dielectric relaxation modes I, II, and III were reexamined. By using the Cole–Cole equation fitting of the frequency dependence of dielectric constant and loss, we obtained more precise relaxation time data, compared to the data reported in the literature. The(More)