The dielectric properties of as-received and gamma irradiated fused silica

Fontanella, J. J.; Johnston, Richard L.; Sigel, George H.; Andeen, Carl

doi:10.1016/0022-3093(79)90153-4

Cited by 22 publications

(10 citation statements)

References 15 publications

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“…They are responsible for broad quasi-elastic components in the neutron and light-scattering spectra [8,9], in the attenuation of sound waves [10][11][12], and in dielectric loss spectra [13]. The internal friction spectrum of vitreous silica, i.e., its loss angle measured at different frequencies [14], confirms quantitatively the existence of a broad distribution of relaxation rates [10,4].…”

Section: Introductionmentioning

confidence: 75%

Low-frequency losses in silica glass at low temperature

Travasso

Bosi

Dari

et al. 2009

Materials Science and Engineering: A

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Section: Introductionmentioning

confidence: 75%

Low-frequency losses in silica glass at low temperature

Travasso

Bosi

Dari

et al. 2009

Materials Science and Engineering: A

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“…For example, it may be associated with oxygen defects. This is not unreasonable because it is thought that nonbridging oxygens give rise to a very-low-temperature relaxation in fused silica . Perhaps both off-center titaniums and oxygen defects are responsible for the low-temperature relaxation region.…”

Section: Resultsmentioning

confidence: 99%

Size Effects Observed via the Electrical Response of BaTiO₃ Nanoparticles in a Cavity

et al. 2012

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Barium titanate (BaTiO3) is one of the most widely used electronic materials. The origin of changing structural and electronic behavior between larger and smaller nanoparticles in BaTiO3 has been extensively investigated. Here, the dielectric loss measured for BaTiO3 or BaZrO3 particles in a cavity at audio frequencies (10–105 Hz) and low temperatures (5.5–350 K) is reported. Distinct differences were found between small (50–100 nm diameter/cubic) and large (>200 nm diameter/tetragonal at room temperature) BaTiO3 particles. Isochronal relaxation features observed around 20 K showed differing shape and dynamics (50–100 nm particles: broad peak, E act ≈ 0.04 eV, log10(f pre(s)) ≈ 14.7; >200 nm particles: sharp peak, E act ≈ 0.025 eV and log10(f pre(s)) ≈ 12, with a shoulder). The low-temperature relaxations are attributed to the motion of off-center titanium ions. In support of this identification, low-temperature relaxations were not observed in BaZrO3 nanoparticles. Finally, structural change features were observed at about 180 and 270 K in the larger BaTiO3 particles (rhombohedral at low temperature) but not in the smaller particles (cubic at all temperatures). The results provide a new set of testable bounds that should contribute to the understanding of nanoparticle-sized BaTiO3, in particular, and ferroelectric behavior in perovskites, in general.

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“…In our method, an ac electric field in a wide frequency range from kilohertz to megahertz is applied to explore the strong interactions between inorganic substances incorporated into the dumbbells. It was reported that titania has a dielectric constant (47 at 1 kHz 22 and 5.5 at 1 MHz 23 ) higher than that of silica (3.8 at 1 kHz 24 and ∼2.0 at 1 MHz 25 ). Three different asymmetric dumbbells, incorporating a silica, titania, or titania/silica (titania:silica = 75:25 vol %) sphere, are employed to examine the interactions between the inorganic parts of dumbbells under the electric field.…”

Section: ■ Introductionmentioning

confidence: 97%

Directed Orientation of Asymmetric Composite Dumbbells by Electric Field Induced Assembly

et al. 2012

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Assembly and directed orientation of anisotropic particles with an external ac electric field in a range from 1 kHz to 2 MHz were studied for asymmetric composite dumbbells incorporating a silica, titania, or titania/silica (titania:silica = 75:25 vol %) sphere. The asymmetric composite dumbbells, which were composed of a polymethylmethacrylate (PMMA)-coated sphere (core-shell part) and a polystyrene (PSt) lobe, were synthesized with a soap-free emulsion polymerization to prepare PMMA-coated inorganic spheres and another soap-free emulsion polymerization to form a polystyrene (PSt) lobe from the PMMA-coated inorganic spheres. The composite dumbbells dispersed in water were directly observed with optical microscopy. The dumbbells incorporating a silica sphere oriented parallel to an electric field in the whole frequency range and they formed a pearl chain structure at a high frequency of 2 MHz. The titania-incorporated dumbbells formed chain structures, in which they contacted their core-shell parts and oriented perpendicularly to a low-frequency (kHz) field, whereas they oriented parallel to a high-frequency (MHz) field. Since the alignment of dumbbells in the chains depends not only on the interparticle forces but also on the torque that the induced dipoles in the dumbbells experience in the electric field, the orientation of dumbbells perpendicular to the electric field was the case dominated by the interparticle force, whereas the other orientation was the case dominated by the torque. The present experiments show that the incorporation of inorganic dumbbells is an effective way to control the assembled structure and orientation with an electric field.

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The dielectric properties of as-received and gamma irradiated fused silica

Cited by 22 publications

References 15 publications

Low-frequency losses in silica glass at low temperature

Low-frequency losses in silica glass at low temperature

Size Effects Observed via the Electrical Response of BaTiO₃ Nanoparticles in a Cavity

Directed Orientation of Asymmetric Composite Dumbbells by Electric Field Induced Assembly

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The dielectric properties of as-received and gamma irradiated fused silica

Cited by 22 publications

References 15 publications

Low-frequency losses in silica glass at low temperature

Low-frequency losses in silica glass at low temperature

Size Effects Observed via the Electrical Response of BaTiO3 Nanoparticles in a Cavity

Directed Orientation of Asymmetric Composite Dumbbells by Electric Field Induced Assembly

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Product

Resources

About

Size Effects Observed via the Electrical Response of BaTiO₃ Nanoparticles in a Cavity