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

Onoda, Hiroaki; Yamasaki, Taro

doi:10.1007/s40145-013-0074-9

Cited by 4 publications

(2 citation statements)

References 11 publications

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“…The XRD patterns of lanthanum phosphate powders calcined at 1500°C with various mass ratios of H 3 PO 4 are shown in Figure 1. The monoclinic LaPO 4 (JCPDS # 32-0493) [6] is the dominant phase in all sample powders, while traces of La 3 PO 7 (JCPDS # 49-1023) [19] for a mass ratio of 10:10:3 and La(PO 3 ) 3 (JCPDS file # 33-0718) [20] for 10:10:5 and 10:10:6 are also observed. Relatively pure monoclinic LaPO 4 phase was obtained only for a mass ratio of 10:10:4 ( Figure 1(b)), so powder under this processing condition was used subsequently.…”

Section: Phases and Morphologies Of Lanthanum Phosphate Powdersmentioning

confidence: 87%

Mechanical and dielectric properties of porous lanthanum orthophosphate materials with TiO₂ addition via foam-gelcasting

Qiao

Liu

2020

Journal of Asian Ceramic Societies

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Lanthanum orthophosphate (LaPO 4 ) powder was prepared by a solid-liquid precipitation reaction of lanthanum carbonate powder with H 3 PO 4 in order to fabricate porous LaPO 4 materials. The phase transition and morphology evolution of the reaction products were found to be dependent mainly on the mass ratios of reactants and calcination temperatures. Porous materials using as-synthesized single-phase LaPO 4 powders and TiO 2 additives via direct foam-gelcasting exhibit large spherical-shaped cells without preferred orientation. The bulk density increases with the increase of sintering temperatures, as evidenced by bigger strut thickness, smaller cell and window sizes and lower inter-connectivity. Porous LaPO 4 bulk ceramic with 5 wt% TiO 2 addition sintered from 1100°C to 1500°C shows a porosity within 66.80-82.03% and a compressive strength from 4.0 to 17.2 MPa. The compressive strength dependence on the relative density follows a power-law relationship with an exponent value of 2.45. While imaginary parts of dielectric permittivity of the porous LaPO 4 materials measured over the X-band frequencies (8.2-12.4 GHz) depend weakly on the frequency and TiO 2 addition, the real parts are affected strongly by TiO 2 addition and sintering temperatures and fall within the range between 1.9 and 3.5 in this study. ARTICLE HISTORY

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Section: Phases and Morphologies Of Lanthanum Phosphate Powdersmentioning

confidence: 87%

Mechanical and dielectric properties of porous lanthanum orthophosphate materials with TiO₂ addition via foam-gelcasting

Qiao

Liu

2020

Journal of Asian Ceramic Societies

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“…The hydrothermal hot-pressing method [60] was proposed to avoid thermal decomposition of rare earth phosphates, which are susceptible to thermal decomposition. Samples of lanthanum and yttrium ortho- and poly-phosphates LaPO 4 , La(PO 3 ) 3 [100], YPO 4 , Y(PO 3 ) 3 were fabricated using HHP.…”

Section: Recent Developments In Near Room Temperature Consolidation: ...mentioning

confidence: 99%

A review of cold sintering processes

Grasso

Biesuz

Zoli

et al. 2020

Advances in Applied Ceramics

195

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The need to reduce the energy consumed and the carbon footprint generated by firing ceramics has stimulated research to develop consolidation techniques operating at lower temperatures, ideally not exceeding 300°C. This has been realised in Ultra Low Energy Sintering (ULES) using high pressure (hundreds of MPa) in the presence of a transient liquid phase, which accelerates plasticity, grain boundary/surface diffusion and mass transport. Several ULES techniques have been developed in the past 50 years, and a common feature of all of them is low temperature consolidation, through mechanisms not yet fully understood, enabling multi-material integration (e.g. organics and inorganics). This research could transform the traditional firing of functional and structural materials. Early stage work on ULES, started in the 1960s, clearly demonstrated cohesion between the compacted particles exceeding what was possible if simply produced by Van der Waals bonding, suggesting the formation of primary inter-particle bonds. Surprisingly, metals Cold Sintered (CS) in dry conditions at room temperature can be even stronger than their counterparts sintered at high temperatures (typically ≈ 2/3 T m). Hydrothermal Hot Pressing (HHP) was originally conceived in the context of sustainability and environmental preservation, with some examples being the concept of 'synthetic rock' for immobilisation of toxic/radioactive waste and the consolidation of high surface area porous ceramics for filtration. Follow up work on HHP considered the possibility of recreating in the lab bio-mineralisation using hydroxyapatite and bioglass (including hybrids) as proof of concept. Recent work on the Cold Sintering Process has demonstrated the potential to bridge the processing gap of multimaterial devices (sensors, batteries, 5G antennas, electronic components and biomaterials), enabling integration of polymers, ceramics and metals without degradation of the individual components both at the bulk and interface level. The absence of heating unlocks grain boundary design to an unprecedented level, offering further degrees of freedom in tuning functional properties. This review provides a wide perspective on room temperature consolidation, and covers the related but fragmented work published (≈ 450 papers) during the past 50 years, encompassing the relevant work developed in different disciplines including chemistry, physics, biology and geoscience. Liquid-assisted or liquid-mediated phenomena involving diffusion, plasticity, rheology, and grain growth are still largely unexplored in material science. The purpose of bringing together this literature is to build a general and multidisciplinary knowledge to guide future research directions. Both the reduction of energy consumption and carbon footprint are driving the growing interest in ULES, which could reinvent the concept of sintering, 'rendering kilns obsolete'. Also, ULES has the potential to produce new classes of materials that cannot be fabricated using conventional routes.

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Polyacrylamide gel synthesis, structure and optical properties of LaP3O9:Eu3+ phosphors

et al. 2015

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

Cited by 4 publications

References 11 publications

Mechanical and dielectric properties of porous lanthanum orthophosphate materials with TiO₂ addition via foam-gelcasting

Mechanical and dielectric properties of porous lanthanum orthophosphate materials with TiO₂ addition via foam-gelcasting

A review of cold sintering processes

Polyacrylamide gel synthesis, structure and optical properties of LaP3O9:Eu3+ phosphors

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

Cited by 4 publications

References 11 publications

Mechanical and dielectric properties of porous lanthanum orthophosphate materials with TiO2 addition via foam-gelcasting

Mechanical and dielectric properties of porous lanthanum orthophosphate materials with TiO2 addition via foam-gelcasting

A review of cold sintering processes

Polyacrylamide gel synthesis, structure and optical properties of LaP3O9:Eu3+ phosphors

Contact Info

Product

Resources

About

Mechanical and dielectric properties of porous lanthanum orthophosphate materials with TiO₂ addition via foam-gelcasting

Mechanical and dielectric properties of porous lanthanum orthophosphate materials with TiO₂ addition via foam-gelcasting