Influence of Thermal Annealing on Terahertz Dielectric Properties of ZnGeP2 Crystals

Pb(Zn1/3Nb2/3)O3-based ceramics were thermally annealed at 700–900 °C for 4 h. Both the relative dielectric constant and dissipation factor in the vicinity of transition temperature were increased when the specimens were thermally annealed at 700–900 °C, but the diffusion factor was decreased. After thermal annealing, the maximum dielectric constant Km was increased from about 11,000 to 26,000. These phenomena can be related to the domain wall motion and the elimination of internal stress.

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The Interfacial Characteristics of Ba0.6Sr0.4TiO3 Films Deposited by Radio Frequency Magnetron Sputtering

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.336-338.374 ◽

2007 ◽

Vol 336-338 ◽

pp. 374-376

Author(s):

Jia Xuan Liao ◽

C.R. Yang ◽

J.H. Zhang ◽

H. Chen ◽

C.L. Fu ◽

...

Keyword(s):

Dielectric Properties ◽

Magnetron Sputtering ◽

Radio Frequency ◽

Thermal Annealing ◽

Transition Layer ◽

Radio Frequency Magnetron ◽

Radio Frequency Magnetron Sputtering ◽

Si Substrates ◽

Bst Films ◽

Interfacial Characteristics

Ba0.6Sr0.4TiO3 (BST) thin films deposited on Pt/Ti/SiO2/Si substrates by radio frequency magnetron sputtering and crystallized by rapid thermal annealing (RTA) exhibit much thinner BST/Pt interfacial transition layer and higher dielectric properties than the films crystallized by conventional thermal annealing (CTA). HRTEM observations show that the transition layer is 2-3nm thick for RTA and 4-5nm thick for CTA. XPS investigations display that the transition layer is composed of perovskited BST phase and non-perovskited BST phase, and RTA corresponds to much less non-perovskited BST phase than CTA. The reason for non-perovskited BST phase and the dielectric properties of BST films are also presented.

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Preparation of TiO2 Polymer Nanodielectrics via a Solvent-Based Technique

ASME 2010 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, Volume 2 ◽

10.1115/smasis2010-3883 ◽

2010 ◽

Author(s):

Payam Khodaparast ◽

Zoubeida Ounaies

Keyword(s):

Dielectric Constant ◽

Dielectric Properties ◽

Dielectric Permittivity ◽

Thermal Annealing ◽

High Dielectric Constant ◽

Maxwell Model ◽

Nanocomposite Films ◽

Pvdf Matrix ◽

High Dielectric ◽

Considerable Enhancement

The effect of adding surface-functionally treated TiO2 nanoparticles on dielectric properties of PVDF matrix was investigated. Porosity of the nanocomposite films showed to have an impact on dielectric permittivity results. Thermal annealing was proposed as an effective way to overcome the porosity problem. By combination of surface treatment of particles and thermal annealing of nanocomposite films, considerable enhancement in dielectric permittivity of TiO2-PVDF nanocomposites was achieved. The experimental results were far higher than theoretical values based on Maxwell model, indicating the presence of an active interphase with high dielectric constant in the system.

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