Nanocrystallization of Bi 0.5 Na 0.5 TiO 3 piezoelectric material

D’Assunção

Micro & Optical Tech Letters

et al. 2013

A low profile and dual band rectangular dielectric resonator antenna (DRA) based on high permittivity BaTiO3 is proposed. The antenna main characteristics are investigated for wireless communication system applications at the frequency band from 6.0 to 8.0 GHz. The antenna design is performed using Ansoft HFSS through the finite element method. Antenna prototypes are built and measured on a vector network analyzer (R&S ZVB14 model) for comparison purpose. Agreement between simulated and measured results is observed. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2759–2763, 2013

Section: Experimental Technique—chemical Processmentioning

confidence: 99%

Aperture coupled BaTiO₃ based dielectric resonator antenna with dual‐band

D’Assunção

Micro & Optical Tech Letters

et al. 2013

“…First, the compound from CaO/TiO 2 was prepared in a well‐defined stoichiometric amount by mixture method of calcium and titanium oxides at high temperatures. The fabricated compound provides a synthesis route that form conventional mixed oxides with a relatively low‐cost production [4]. The direct synthesis of calcium titanate is given by Eqs.…”

Section: Experimental Technique: Preparation Of Calcium Titanatementioning

confidence: 99%

“…This has been done to bring together different services into a single compact unit handset, while keeping high‐performance standards. To accomplish that it is necessary to develop small antennas that are able to operate in several frequencies [1–9]. Dielectric resonator antennas (DRAs) are integrated structures with predefined formats and are able to radiate if the dielectric constant is high (ε r > 10) [2].…”

Section: Introductionmentioning

confidence: 99%

Small size dual‐band rectangular dielectric resonator antenna based on calcium titanate (CaTiO₃)

D’Assunção

Micro & Optical Tech Letters

et al. 2012

A rectangular dielectric resonator antenna (DRA) based on CaTiO3 with low profile, dual‐band and high dielectric constant is proposed as a candidate for application in wireless communication systems at the microwave band. The proposed geometry is composed by a dielectric resonator mounted on a microstrip line section that is used as the feeding element. The antenna analysis is performed using Ansoft HFSS that implements the finite element method. Measured results are shown for several DRA prototypes. A good agreement between numerical and experimental results is observed. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:976–979, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26729

“…In addition, high energy milling was used in order to obtain (Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 TiO 3 nanometric powders [29]. Finally, nanostructured NBT-BaTiO 3 whiskers were elaborated topochemically using Na 2 Ti 6 O 13 as a host structure [30] and NBT nanocrystals were synthesized from either Bi 2 Ti 4 O 11 [31] or Bi 4 Ti 3 O 12 [32].…”

Section: Introductionmentioning

confidence: 99%

Randomly organized and self-assembled Na0.5Bi0.5TiO3 nanodots elaborated by sol–gel and pulsed laser deposition routes

et al. 2013

This work reports for the first time on the elaboration, by both chemical (sol-gel) and physical (Pulsed Laser Deposition) routes, of lead-free ferroelectric Na 0.5 Bi 0.5 TiO 3 nanodots deposited on bare c-sapphire single crystal substrates presenting a 5° miscut angle along the [110] direction. Prior to any deposition, the sapphire substrates were treated at 1350°C, during 24h in air, in order to increase the height of the surface steps, reaching by this way ~ 8nm. The experimental parameters adjusted for the growth of Na 0.5 Bi 0.5 TiO 3 dots were the concentration of sols and the number of laser pulses (50 and 100) for the sol-gel and pulsed laser deposition routes, respectively. Whereas the sol-gel route leads to randomly organized Na 0.5 Bi 0.5 TiO 3 nanodots in respect to the surface steps, the pulsed laser deposition route provokes the selfassembly for some important proportion of these dots along the same surface steps. Despite the lack of organization for the sol-gel dots, the latter present a much more regular distribution in size (~100 and ~10-20 nm as average lateral dimensions and height, respectively) compared to dots deposited by laser ablation, where three different populations of grains can be observed. In each case, the dots do not seem to be epitaxially grown.