Fast synthesis of NaNbO3 and K0.5Na0.5NbO3 by microwave hydrothermal method

López-Juárez, Rigoberto; Castañeda-Guzmán, R.; Villafuerte-Castrejón, M.E.

doi:10.1016/j.ceramint.2014.06.065

Cited by 42 publications

(14 citation statements)

References 33 publications

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“…Upon compaction and subsequent annealing at 500 °C, the surface morphology of the final pellet changes with respect to the un‐treated powders. As a consequence of the annealing treatment and uniaxial pressure, evidenced in Figure B, the pores definitely disappeared together with a significant crystal growth and the presence of small particles, in agreement with other synthetic procedures …”

Section: Resultssupporting

confidence: 89%

Local Piezoelectric Behavior of Potassium Sodium Niobate Prepared by a Facile Synthesis via Water Soluble Precursors

Senes

Iacomini

Domingo

et al. 2018

Physica Status Solidi (a)

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Due to the ever‐increasing restrictions connected to the use of toxic lead‐based materials, the developing of lead‐free piezoceramics has become one of the most urgent tasks. In this context, potassium sodium niobate materials (KNN) have attracted a lot of interest as promising candidates due to their excellent piezo properties. For this reason, many efforts have been addressed to optimize the synthesis process now suffering by several drawbacks including the high volatilization of potassium and sodium at the conventional high temperature treatments and the use of expensive metal precursors. To overcome these issues, a new modified Pechini method to synthesize single phase K0.5Na0.5NbO3 powders, from water soluble metal precursors, is presented. Microstructural and structural parameters are characterized by X‐ray diffraction (XRD). Depending on the amount of citric acid added to the starting reagents, two pure single‐phase K0.5Na0.5NbO3 (2 g citric acid) and K0.3Na0.7NbO3 (0.2 g citric acid), respectively, are obtained with a good crystallinity at a moderate temperature of 500 °C. The piezo responses of the as calcined systems are tested by piezoresponse force microscopy (PFM). K0.5Na0.5NbO3 exhibits a much higher response with respect to the other phase, which relates to the larger crystallinity and to the chemical composition.

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Section: Resultssupporting

confidence: 89%

Local Piezoelectric Behavior of Potassium Sodium Niobate Prepared by a Facile Synthesis via Water Soluble Precursors

Senes

Iacomini

Domingo

et al. 2018

Physica Status Solidi (a)

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“…Finally, in order to improve the reaction kinetic of the KNN formation and further reduce the synthesis time, the hydrothermal approach can be combined with microwave heating . Temperature below 200 °C and annealing time lower than 7 h allow to obtain crystalline KNN systems and avoid secondary phases typically produced under prolonged dwell time and high processing temperatures (>600°).…”

Section: Advanced Synthesis and Properties Of Knn And Related Composimentioning

confidence: 99%

Advanced Synthesis on Lead‐Free K_xNa_(1−x)NbO₃ Piezoceramics for Medical Imaging Applications

Garroni

Senes²,

Iacomini³

et al. 2018

Physica Status Solidi (a)

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Ultrasonic imaging system is a non‐invasive medical imaging technique that has become one of the most widely used diagnostic tools in modern medicine for detecting prenatal anomalies and deep screening of biological tissues. One of the core components of the ultrasound system is represented by the probe where is located the transducer which produces mechanical energy in response to electrical signals, and conversely, produce electrical signals in response to mechanical stimulus. The ultrasound transducer in the probe is generally made of a piezoelectric ceramic material such as lead zirconate titanate (PZT), which present two important limitations as the presence of toxic material as the lead, and low acoustic impedance ascribable to its high density. For these reasons, it is necessary to focus the research on new eco‐friendly piezoelectric materials with properties comparable with PZT. Among them potassium sodium niobate is considered as a leading lead‐free candidate to replace lead‐based piezoceramics, resulting the most promising. In this review, the most relevant and advanced synthesis approaches and the unique properties of this class of lead‐free piezoceramics are presented in detail.

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“…Interestingly enough, this kind of KNN material (modified or not) has been prepared by the “spray-drying” method, as an alternative to the ceramic method, yielding nano-sized powders which can be sintered to prepare ceramics of high density (96%) with improved properties [131,132]. With the same strategy, trying to avoid potassium or sodium losses by sublimation, these ceramics have been prepared by “fast chemistry” methods, such as spark-plasma synthesis (SPS) and microwave-assisted methods [133,134]. Nevertheless, regarding the control of grain growth, it is worth noting that self-orientation and agglomeration of nanoparticles can usually be observed besides microstructures consisting of domains and domain walls (Figure 8) [135], all these issues affecting the piezoelectric properties [136].…”

Section: (K05na05)nbo3 (Knn)mentioning

confidence: 99%

Towards Lead-Free Piezoceramics: Facing a Synthesis Challenge

Villafuerte‐Castrejon

Morán

Reyes-Montero

et al. 2016

Materials

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The search for electroceramic materials with enhanced ferro-pyro-piezoelectric properties and revealing the perovskite type structure has been the objective of a significant number of manuscripts reported in the literature. This has been usually carried out by proposing the synthesis and processing of new compounds and solid solution series. In this work, several methods to obtain ferro-pyro-piezoelectric families of materials featuring the well-known ABO3 perovskite structure (or related) such as BaTiO3, Ba1–xCaxTi1–yZryO3, (Bi0.5Na0.5)TiO3, (K0.5Na0.5)NbO3 and their solid solutions with different cations either in the A or B positions, are presented. For this kind of materials, the challenge for obtaining a single phase compound with a specific grain size and morphology and, most importantly, with the adequate stoichiometry, will also be discussed. The results reviewed herein will be discussed in terms of the tendency of working with softer conditions, i.e., lower temperature and shorter reaction times, also referred to as soft-chemistry.

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Fast synthesis of NaNbO3 and K0.5Na0.5NbO3 by microwave hydrothermal method

Cited by 42 publications

References 33 publications

Local Piezoelectric Behavior of Potassium Sodium Niobate Prepared by a Facile Synthesis via Water Soluble Precursors

Local Piezoelectric Behavior of Potassium Sodium Niobate Prepared by a Facile Synthesis via Water Soluble Precursors

Advanced Synthesis on Lead‐Free K_xNa_(1−x)NbO₃ Piezoceramics for Medical Imaging Applications

Towards Lead-Free Piezoceramics: Facing a Synthesis Challenge

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Fast synthesis of NaNbO3 and K0.5Na0.5NbO3 by microwave hydrothermal method

Cited by 42 publications

References 33 publications

Local Piezoelectric Behavior of Potassium Sodium Niobate Prepared by a Facile Synthesis via Water Soluble Precursors

Local Piezoelectric Behavior of Potassium Sodium Niobate Prepared by a Facile Synthesis via Water Soluble Precursors

Advanced Synthesis on Lead‐Free KxNa(1−x)NbO3 Piezoceramics for Medical Imaging Applications

Towards Lead-Free Piezoceramics: Facing a Synthesis Challenge

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Advanced Synthesis on Lead‐Free K_xNa_(1−x)NbO₃ Piezoceramics for Medical Imaging Applications