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Lee, Wen−Hsi; Groen, W.A.; Schreinemacher, Herbert; Hennings, D.

doi:10.1023/a:1009937310444

Cited by 71 publications

(35 citation statements)

References 9 publications

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“…Impurity mass fraction was 0.02%. The particle size of the powder was determined by SEM (Philips XL20, Netherlands).The specific surface area was measured by the single-point BET method with liquid N 2 (Flowsorb 2300, Micromeritics Instrument Corp., Norcross, GA), and phase composition was analyzed using XRD (D/max-2200 PC, Rigaku Co. Ltd., Tokyo, Japan).Parameters of physical properties of powder were listed in Table I 3 and mixed for 24 h using stabilized zirconia balls in ethanol media. After being dried, the powder was granulated using ploy(vinyl alcohol) (PVA) binder and formed under a uniaxial pressure of 1000 kg/cm 2 , and pressed pellets (φ14 mm×2 mm) were sintered at 1275 °C for 2 h in air with a heating rate of 10 °C/min.…”

Section: Methodsmentioning

confidence: 99%

“…Such synthesized BaTiO 3 powder have a limited size range, microstructural variance, nonstoichiometric composition, and poor electric reproducibility. Hydrothermal fabrication method, instead, can result in tetragonal sub-micrometer BaTiO 3 powder with high-purity, complete crystallization, and without agglomeration. Particularly, the doping with rare earth oxides can restrain the abnormal grain growth.…”

Section: Introductionmentioning

confidence: 99%

“…Hennings [3], Kishi [4], Makovec [5] and Venigalla [6] have investigated the rare earth (Ho, Y, Sm, La) incorporation into BaTiO 3. The starting powder they used were prepared by solid phase reaction or introducing additional elements (Mg, Zr) into the composition.…”

Section: Introductionmentioning

confidence: 99%

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Microstructure and dielectric properties of dysprosium-doped barium titanate ceramics

Chen

et al. 2005

Cerâmica

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The substitution behavior and lattice parameter of barium titanate between solid_solubility with a dopant concentration in the range of 0.25 to 1.5 mol% are studied. The influences of dysprosium-doped fraction on the grain size and dielectric properties of barium titanate ceramic, including dielectric constant and breakdown electric field strength, are investigated via scanning electronic microscopy, X-ray diffraction and electric property tester. The results show that, at a dysprosium concentration of 0.75 mol%, the abnormal grain growth is inhibited and the lattice parameters of grain rise up to the maximum because of the lowest vacancy concentration. In addition, the finegrain and high density of barium titanate ceramic result in its excellent dielectric properties. The relative dielectric constant (25 °C) reaches to 4100. The temperature coefficient of the capacitance varies from -10 to 10% within the temperature range of -15 °C -100 °C, and the breakdown electric field strength (alternating current) achieves 3.2 kV/mm. These data suggest that our barium titanate could be used in the manufacture of high voltage ceramic capacitors.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Microstructure and dielectric properties of dysprosium-doped barium titanate ceramics

Chen

et al. 2005

Cerâmica

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“…It was observed that, certain lanthanides, such as Ho, Dy, Sm and sometimes Er, can improve the resistance of the magnesium ferrite due to electrochemical or time dependent failure, when fired in low oxygen partial pressures [3]. It is already mentioned that -magic‖ dopants can choose their site occupancy as a result of the local Mg/Fe ratio and oxygen partial pressure during firing [4] and since these dopants were also termed -amphoteric‖ due to the site change of a well defined valence dopant and causing a change of the relative charge [5].…”

Section: Introductionmentioning

confidence: 99%

Electro Paramagnetic Resonance Studies to Determine the Dopant site Occupancy of Dy-Sm doped Magnesium Ferrite for Micro Strip Patch Antenna Substrate

Naidu¹,

Devi²,

Legadevi³

et al. 2012

IJCA

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In the present study, site occupancy of Dysprosium (Dy), Samarium(Sm) doped Magnesium ferrite were investigated by electro paramagnetic resonance (EPR). Point charge calculations were used to predict the EPR spectrum of each lanthanide in A-and B-sites. Different EPR spectra are expected for A-versus B-site substitution when Sm 3+ cation it is on the A-site. EPR signal intensity suggested the amphoteric behavior due to Dy 3+ in the magnesium ferrite material as Dy 3+ was found to be a B-site dopant. These studies will be helpful for the analytical studies of permittivity and permeability to design Microstrip patch antenna to be used in pervasive computing.

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“…it can be +2 or +3, and these valences give different ionic sizes. Another difficulty is from the findings of Tsur et al [5] and Lee et al [6] on rare-earth ion doped BaTiO 3 and Ba(Ti, Zr)O 3 ceramics that Dy ion is amphoteric, i.e. it can go to either A-site (Ba) or B-site (Ti, Zr).…”

Section: Introductionmentioning

confidence: 99%

Effects of dysprosium oxide addition in bismuth sodium titanate ceramics

2007

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This research focuses on the preparation and characterization of dysprosium-doped bismuth sodium titanate (BNT) ceramics. The compounds were prepared using the conventional mixed-oxide method. The amount of dysprosium oxide used was varied from 0 to 2 at.%. The mixed powders were calcined at 800°C and checked for phase purity using X-ray diffraction technique. The powders were then cold-pressed into small pellets which were subsequently sintered at 1050°C for 2 h. The results from density measurement and SEM micrographs showed that highly dense and high-purity ceramics were obtained. The grain size of Dy-doped samples was found to decrease with increasing Dy content. Compared to pure BNT, the addition of Dy 2 O 3 in BNT ceramics slightly increased the dielectric constant values near room temperature. In addition, the Dy doping resulted in a more diffused transition temperature, less frequency dependence of the dielectric constant and very low values of the dielectric loss.

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Cited by 71 publications

References 9 publications

Microstructure and dielectric properties of dysprosium-doped barium titanate ceramics

Microstructure and dielectric properties of dysprosium-doped barium titanate ceramics

Electro Paramagnetic Resonance Studies to Determine the Dopant site Occupancy of Dy-Sm doped Magnesium Ferrite for Micro Strip Patch Antenna Substrate

Effects of dysprosium oxide addition in bismuth sodium titanate ceramics

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