Synthesis and Electrical Conductivity of Tetra-Valent Cerium Polyphosphate Bulks

Onoda, Hiroaki; Inagaki, Yousuke; Kuwabara, Akihide; Kitamura, Naoto; Amezawa, Koji; Nakahira, Atsushi; Tanaka, Isao

doi:10.3363/prb.23.20

Cited by 16 publications

(20 citation statements)

References 14 publications

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“…The filling factor is approximately 70%, which is calculated from the ideal density of lanthanum polyphosphate. This percentage is lower than that of the phosphate bulk samples synthesized by the HHP process in the previous experiments [8][9][10]. The low filling factor can potentially absorb the physical stress.…”

Section: Density Of Bulk Lanthanum Polyphosphatesmentioning

confidence: 60%

Synthesis of bulk lanthanum polyphosphate and other rare earth phosphates through hydrothermal hot-pressing

Onoda

Yamasaki

2013

J Adv Ceram

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Bulk samples of lanthanum polyphosphate were synthesized through a hydrothermal hot-pressing (HHP) process. In this process, pressing temperature, pressure and volume of water were varied in order to improve the density and strength of the resulting materials. The strength of the bulk samples was estimated through drilling and ultrasonic treatments. In order to improve the strength of the materials, the use of microwave irradiation was examined. Lanthanum polyphosphate formed porous bulk samples with a filling factor of approximately 70%, which was calculated from real and theoretical densities. With respect to machinable strength, a drilled hole greater than 7.0 mm in diameter was obtained on some bulk samples, and the diameter of the samples was 14 mm. The HHP process is a useful method for obtaining bulk samples of lanthanum polyphosphate. Bulk lanthanum polyphosphate containing water crumbled easily to a powder form upon ultrasonication. However, these bulk samples retained their shape upon ultrasonication, despite containing water, after exposure to microwave irradiation, and also experienced minimal weight loss. Furthermore, to study the effect of microwave heating, bulk lanthanum orthophosphate, yttrium orthophosphate and polyphosphate were also examined.

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Section: Density Of Bulk Lanthanum Polyphosphatesmentioning

confidence: 60%

Synthesis of bulk lanthanum polyphosphate and other rare earth phosphates through hydrothermal hot-pressing

Onoda

Yamasaki

2013

J Adv Ceram

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“…Only a conventional calcination technique has been used to prepare CeP 2 O 7 and Ce(PO 3 ) 4 in previous studies [3,7,8,15,[29][30][31] 4 were adequately mixed in an agate mortar. The mixture was stored in a porcelain crucible with an insulation layer and directly irradiated at various MW powers for different times.…”

Section: ) On U(vi)mentioning

confidence: 99%

“…CeP 2 O 7 powder can reportedly be obtained by the dehydration of Ce(HPO 4 ) 2 ÁxH 2 O, which was prepared by heating H 3 PO 4 and Ce(SO 4 ) 2 ÁxH 2 O under reflux conditions, using a heat treatment at 600°C for 16 h. CeO 2 and 85 % H 3PO 4 have also been calcined at 300°C for 8 h[3], or at 700°C for 20 h[29]. Amorphous CeP 2 O 7 powder has been obtained as well using Ce(SO 4 ) 2 Á4H 2 O and Na 4 P 2 O 7 as initial materials at 80°C for 24 h; crystallization from the amorphous phase occurred at around 500°C to form crystalline cerium pyrophosphate[30].…”

mentioning

confidence: 99%

Microwave-assisted rapid synthesis of cerium phosphates and their adsorption on uranium(VI)

Wang

Ning

et al. 2015

Res Chem Intermed

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Cerium phosphates have been successfully synthesized under microwave irradiation in the absence of organic solvent. The effects of different molar ratios of phosphoric acid (85 %) to cerium hydroxide on the product phosphates were investigated. A single-phase CeP 2 O 7 compound and a mixture of tetravalent cerium pyrophosphate (CeP 2 O 7 ) and metaphosphate (Ce(PO 3 ) 4 ) were synthesized at 800 W for 5 min under microwave irradiation when the mole ratio of H 3 PO 4 to Ce(OH) 4 was equal to 2 and 2.5-4, respectively. In the presence of chemometric excess of H 3 PO 4 (mole ratio of H 3 PO 4 to Ce(OH) 4 is between 5 and 6), a singlephase Ce(PO 3 ) 4 compound can be prepared at 480 W for 10 min under microwave irradiation. Scanning and transmission electron microscope images showed that particle sizes of CeP 2 O 7 and Ce(PO 3 ) 4 were 0.1-3 and 1-5 lm, respectively. The adsorption properties of CeP 2 O 7 and Ce(PO 3 ) 4 on uranium(VI) were examined. In the same condition, uranium(VI) was removed by Ce(PO 3 ) 4 more effectively than CeP 2 O 7 , and there are greater advantages for products synthesized under microwave irradiation than those calcination products on adsorption of uranium(VI).

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“…(Shuetz & Caruso, 2002;Meiser et al, 2004). The condensed phosphates have different properties from those of orthophosphates and can therefore be used as novel functional materials , Onoda et al, 2005Briche et al, 2010;Onoda et al, 2010).…”

Section: Introducationmentioning

confidence: 99%

Synthesis and Fluorescence Properties of Europium - Substituted Lanthanum Polyphosphates

Onoda¹,

Funamoto²

2012

JMSR

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Europium-substituted lanthanum polyphosphates (Eu; 0, 1, 2, 3, 4, 5, and 10 mol%) were prepared from lanthanum nitrate, europium nitrate, and sodium polyphosphate solutions. The obtained phosphates were estimated using XRD patterns, TG-DTA curves, SEM images, and particle size distributions. The fluorescence spectra were estimated as functional properties of these phosphate materials. The obtained samples crystallized by heating at 600ºC. Lanthanum polyphosphates were stable from 600 to 850ºC. The 5 mol% europium-substituted lanthanum polyphosphate showed a strong peak at 615 nm.

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Synthesis and Electrical Conductivity of Tetra-Valent Cerium Polyphosphate Bulks

Cited by 16 publications

References 14 publications

Synthesis of bulk lanthanum polyphosphate and other rare earth phosphates through hydrothermal hot-pressing

Synthesis of bulk lanthanum polyphosphate and other rare earth phosphates through hydrothermal hot-pressing

Microwave-assisted rapid synthesis of cerium phosphates and their adsorption on uranium(VI)

Synthesis and Fluorescence Properties of Europium - Substituted Lanthanum Polyphosphates

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