Infrared reflectivity and intrinsic dielectric behavior of RETiTaO6 (RE = Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Yb) microwave ceramics

In this work, we performed infrared reflectivity measurements of RETiTaO6 dielectric ceramics for rare-earth (RE) = Y, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, and Yb. The infrared spectra were analyzed through the four-parameter semi-quantum model based on two orthorhombic (aeschynite and euxenite) structures presented by the ceramics. We discerned the strongest phonon modes that contribute to the intrinsic dielectric behavior of the two families. Then the unloaded quality factors and the dielectric permittivities were estimated at the microwave region. The variations of the intrinsic dielectric response of both systems with RE ion substitution are discussed in terms of changes in their dielectric polarizabilities. It is proposed that the covalency of the RE–O bonds play an important role in the evolution of dielectric permittivity as well as in the sign of the temperature coefficient of the resonant frequency.

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Improvement of Ferroelectric Properties of Lead Zirconate Titanate Thin Films by Ion-substitution using Rare-earth Cations

MRS Proceedings ◽

10.1557/proc-830-d3.3 ◽

2004 ◽

Vol 830 ◽

Author(s):

Hiroshi Nakaki ◽

Hiroshi Uchida ◽

Shoji Okamoto ◽

Shintaro Yokoyama ◽

Hiroshi Funakubo ◽

...

Keyword(s):

Thin Films ◽

Rare Earth ◽

Lead Zirconate Titanate ◽

Ferroelectric Property ◽

Ferroelectric Properties ◽

Lead Zirconate ◽

Crystal Anisotropy ◽

Pzt Film ◽

Zirconate Titanate ◽

Ion Substitution

ABSTRACTRare-earth-substituted tetragonal lead zirconate titanate thin films were synthesized for improving the ferroelectric property of conventional lead zirconate titanate. Thin films of Pb1.00REx (Zr0.40Ti0.60)1-(3x /4)O3 (x = 0.02, RE = Y, Dy, Er and Yb) were deposited on (111)Pt/Ti/SiO2/(100)Si substrates by a chemical solution deposition (CSD). B-site substitution using rare-earth cations described above enhanced the crystal anisotropy, i.e., ratio of PZT lattice parameters c/a. Remanent polarization (Pr) of PZT film was enhanced by Y3+-, Dy3+- and Er3+-substitution from 20 μC/cm2 up to 26, 25 and 26 μC/cm2 respectively, while ion substitution using Yb3+ degraded the Pr value down to 16 μC/cm2. These films had similar coercive fields (Ec) of around 100 kV/cm. Improving the ferroelectric property of PZT film by rare-earth-substitution would be ascribed to the enhancement of the crystal anisotropy. We concluded that ion substitution using some rare-earth cations, such as Y3+, Dy3+ or Er3+, is one of promising technique for improving the ferroelectric property of PZT film.

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Characterization and dielectric behavior of a new dielectric ceramics Ca(Mg1/3Nb2/3)O3–(Ca0.8Sr0.2)TiO3 at microwave frequencies

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2009.04.132 ◽

2009 ◽

Vol 484 (1-2) ◽

pp. 494-497 ◽

Cited By ~ 20

Author(s):

Cheng-Liang Huang ◽

Jhih-Yong Chen ◽

Bing-Jing Li

Keyword(s):

Dielectric Behavior ◽

Microwave Frequencies ◽

Dielectric Ceramics

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Sol-gel preparation and electrical behaviour of Ln: YAG (Ln = Ce, Nd, Ho, Er)

Journal of the Serbian Chemical Society ◽

10.2298/jsc0309677g ◽

2003 ◽

Vol 68 (8-9) ◽

pp. 677-684 ◽

Cited By ~ 15

Author(s):

Edita Garskaite ◽

Darizus Jasaitis ◽

Aivaras Kareiva

Keyword(s):

Rare Earth ◽

Yttrium Aluminum Garnet ◽

Sol Gel ◽

Structural Features ◽

Dielectric Behavior ◽

Homogeneous Distribution ◽

Metallic Behavior ◽

Gel Preparation ◽

Xrd Patterns ◽

Increasing Temperature

A sol-gel method has been developed to prepare pure yttrium aluminum garnet Y3Al5O12 (YAG), and rare-earth substituted (Ce-Y3Al5O12, Nd-Y3Al5O12 Ho-Y3Al5O12, and Er-Y3Al5O12) samples. The XRD patterns of the polycrystalline powders sintered at 1000 ?C showed the formation of monophasic garnet materials. The micro-structural features in the polycristalline samples were studied by scanning electron microscopy. A homogeneous distribution of rare-earth do pants in the YAG lattice was achieved in all of the cases. Electrical conductivity measurements were also performed on the compacts of sol-gel derived Ln-YAG samples. In contrast to the expected dielectric behavior, the conducting properties of the examined specimens indicate metallic behavior with the resistivity increasing gradually with increasing temperature.

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Dielectric and varistor properties of rare-earth-doped ZnO and CaCu3Ti4O12 composite ceramics

Journal of Advanced Dielectrics ◽

10.1142/s2010135x1350001x ◽

2013 ◽

Vol 03 (01) ◽

pp. 1350001 ◽

Cited By ~ 6

Author(s):

Huafei Lu ◽

Yuanhua Lin ◽

Jiancong Yuan ◽

Cewen Nan ◽

Kexin Chen

Keyword(s):

Rare Earth ◽

Sol Gel ◽

Nonlinear Coefficient ◽

Composite Ceramic ◽

Dielectric Behavior ◽

Composite Ceramics ◽

High Dielectric Permittivity ◽

Doped Zno ◽

Co Precipitation ◽

High Dielectric

To investigate the multi-functional ceramics with both high permittivity and large nonlinear coefficient, we have prepared rare-earth Tb -and- Co doped ZnO and TiO 2-rich CaCu3Ti4O12 (TCCTO) powders by chemical co-precipitation and sol–gel methods respectively, and then obtained the TCCTO/ ZnO composite ceramics, sintered at 1100°C for 3 h in air. Analyzing the composite ceramics of the microstructure and phase composition indicated that the composite ceramics were composed of the main phases of ZnO and CaCu3Ti4O12 (CCTO). Our results revealed that the TCCTO/ ZnO composite ceramics showed both high dielectric and good nonlinear electrical behaviors. The composite ceramic of TCCTO: ZnO = 0.3 exhibited a high dielectric constant of ~210(1 kHz) with a nonlinear coefficient of ~11. The dielectric behavior of TCCTO/ ZnO composite could be explained by the mixture rule. With the high dielectric permittivity and tunable varistor behaviors, the composite ceramics has a potential application for the higher voltage transportation devices.

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Evaluation of dielectric behavior by time domain spectroscopy. I. Dielectric response by real time analysis

The Journal of Physical Chemistry ◽

10.1021/j100581a022 ◽

1975 ◽

Vol 79 (14) ◽

pp. 1459-1469 ◽

Cited By ~ 89

Author(s):

Robert H. Cole

Keyword(s):

Real Time ◽

Time Domain ◽

Dielectric Response ◽

Dielectric Behavior ◽

Time Analysis ◽

Time Domain Spectroscopy ◽

Real Time Analysis

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Microwave dielectric properties and applications of rare-earth aluminates

Journal of Materials Research ◽

10.1557/jmr.1999.0018 ◽

1999 ◽

Vol 14 (1) ◽

pp. 114-119 ◽

Cited By ~ 212

Author(s):

Seo-Yong Cho ◽

In-Tae Kim ◽

Kug Sun Hong

Keyword(s):

Rare Earth ◽

Dielectric Properties ◽

Microwave Dielectric Properties ◽

Microstrip Antennas ◽

Substrate Material ◽

Rhombohedral Structure ◽

Quality Factors ◽

Microwave Dielectric ◽

Ionic Size ◽

The Difference

Rare-earth aluminates, LnAlO3 (Ln = Dy, Er, Gd, La, Nd, Pr, Sm, and Y) were prepared using the mixed oxide method, and their microwave dielectric properties were examined at X-band. Most rare-earth aluminates have suitable permittivities and quality factors for applications as dielectric resonators, but a modification of τf is necessary due to the coefficient's large negative value. When considering dielectric properties and lattice matching, YalO3 rather than LaAlO3, was suggested as a promising substrate material for microstrip antennas utilizing high-temperature superconductor thin films. Rare-earth aluminates with a rhombohedral structure exhibited larger permittivities than those with an orthorhombic structure. This difference was attributed to the difference in ionic size and coordination number. It was demonstrated that a nonzero magnetic susceptibility of rare-earth aluminates has an adverse effect on their quality factor. An abrupt variation in the temperature coefficient of permittivity was discussed in terms of oxygen octrahedra tilting.

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