Modifications of micro-pulling-down method for the growth of selected Li-containing crystals for neutron scintillator and VUV scintillation crystals

Pejchal, Jan; Fujimoto, Yutaka; Chani, Valery; Yanagida, Takayuki; Yokota, Yuui; Yoshikawa, Akira; Nikl, M.; Beitlerová, A.

doi:10.1016/j.jcrysgro.2011.11.062

Cited by 19 publications

(7 citation statements)

References 13 publications

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“…Consequently, some predictions of positions of the Ti 3+ /Ti 4+ levels in various compositions is possible as Eu 3+ CT states are known for a vast number of hosts. It also allows for a better understanding of the luminescent properties of Ti in various hosts [69,70,71]. Nevertheless, evaluation of the role of d-or closed-shell elements in energy trapping and in thermoluminescence processes is still a challenge and there are no efficient and universal theoretical tools for that.…”

Section: Introduction To Energy Storage Materialsmentioning

confidence: 99%

Lu2O3-based storage phosphors. An (in)harmonious family

Kulesza

Bolek

Bos

et al. 2016

Coordination Chemistry Reviews

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Section: Introduction To Energy Storage Materialsmentioning

confidence: 99%

Lu2O3-based storage phosphors. An (in)harmonious family

Kulesza

Bolek

Bos

et al. 2016

Coordination Chemistry Reviews

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“…However, a slight amount of another, monoclinic BaLu 2 F 8 phase (JCPDS chart 43-0933) was detected as well (not shown here), even though the optical quality of the crystals was very reasonable in most of the cases. The monoclinic phase was already observed in [13] and it is the probable cause of the cracks. Preliminary BSE measurements confirmed stoichiometric composition of all the samples.…”

Section: Hot-zone Temperature Gradient and The Grown Crystals Of Balumentioning

confidence: 95%

“…Better energy transfer from the matrix or between the rare-earth dopants might be expected. In the past we made first attempt to grow the high-temperature BaLu 2 F 8 single crystal by micro-pulling-down method [12] modifying the hot zone and applying quenching process to prevent the phase transition [13]. However, the hot-zone design facilitated meltdrop due to very shallow temperature gradient and its practical application was difficult [13].…”

Section: Introductionmentioning

confidence: 99%

Crystal growth and scintillation properties of selected fluoride crystals for VUV scintillators

Pejchal

Fukuda

Yamaji³

et al. 2014

Journal of Crystal Growth

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Single crystals of orthorhombic and monoclinic BaLu 2 F 8 doped with Nd and Tm were grown by micro-pulling-down method. The monoclinic (low temperature modification) was grown using LiF flux, while the orthorhombic (high temperature modification) was grown with special hotzone with shallow gradient and employing quenching process. Reasonable scintillation efficiency was achieved for the crystals of the former modification, while no rare-earth ion emission was observed in the latter due to preferential energy transfer to defects. The orthorhombic (low temperature) modification of ErF 3 was grown using LiF flux and hot zone with steep gradient. Quite low scintillation efficiency was found for the Nd-doped sample due to energy migration over the Er 3+ levels. Possibility of using pure ErF 3 as an infra-red scintillator is discussed.

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“…Other technological applications are the fabrication of phosphors [8,9], catalysts [10,11] and sorbents for the selective CO2 capture [12,13]. Among these ceramics, different polymorphs of lithium monoaluminate (α-, β-and γ-LiAlO2) have been the subject of several studies [14][15][16][17][18][19][20][21][22][23][24][25]. For example, LiAlO2 has been reported as a good candidate as host matrix for neutron scintillators [14,15], as electrolyte matrix in molten carbonate fuel cells [16][17][18][19], as well as a candidate for certain luminescent devices [20,21] and heterogeneous catalyst for biodiesel production, [25] among others.…”

Section: Introductionmentioning

confidence: 99%

Nanosized Lithium Aluminate (γ-LiAlO2) Synthesized by EDTA-citrate Complexing Method, Using Different Thermal Conditions

et al. 2019

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Lithium aluminate (LiAlO2) polymorphs have been synthesized by solid-state reaction, but these ceramics usually show certain limitations attributed to the low control on the particle size, morphology and specific surface area. In this sense, different chemical synthesis pathways, citrate precursor among them, have been studied to obtain ultrafine powders exhibiting enhanced textural and morphological features. Synthesis by citrate precursor method would involve the use of alternative chelating agents for the formation of more stable metal-chelate species, such as ethylene-diamine-tetra-acetic acid (EDTA). Thus, the aim of this work was to study the g-LiAlO2 synthesis by EDTA-citrate complexing approach to establish the effect of the synthesis route on the structural and microstructural characteristics of the resultant powders. The synthesized ceramic powders were calcined (600-900°C) and characterized by simultaneous TG-DTA, XRD, SEM, TEM and N2 adsorption-desorption techniques. Crystallization transition process from the precursors to the g-LiAlO2 phase is reported. Results show that chemical synthesis by EDTA-citrate complexing method can produce pure and crystalline g-LiAlO2 nanoparticles at relative low temperatures (700 ºC). The possible formation mechanism is discussed. Resumen. El aluminato de litio (LiAlO2) en sus diferentes fases polimórficas se ha sintetizado por la técnica convencional de reacción en estado sólido; sin embargo, este método presenta ciertas limitaciones desde el punto de vista del control que se tiene en el tamaño de partícula, morfología y área específica. En este sentido, se han estudiado diferentes rutas de síntesis química para la obtención de polvos ultrafinos que presenten propiedades texturales y características morfológicas mejoradas. Entre éstas, se encuentra la síntesis por citratos precursores; un método que además del ácido cítrico, puede involucrar el uso de agentes complejantes o quelantes alternativos para promover la formación de especies más estables. Un ejemplo de lo anterior es el ácido etilendiaminotetraacético o EDTA por sus siglas en inglés. El objetivo de este trabajo es estudiar la síntesis del g-LiAlO2 por el método del citrato precursor-EDTA y establecer el efecto de la ruta de síntesis sobre las características estructurales y microestructurales de los compuestos obtenidos. Los polvos cerámicos sintetizados fueron calcinados a diferentes temperaturas (600-900 ºC) y caracterizados por diferentes técnicas como ATG-ATD, DRX, MEB, MET y adsorción-desorción de N2 a baja presión. Se estudió el proceso de descomposición y cristalización de los precursores hasta la obtención del óxido metálico de aluminato de litio. Los resultados muestran que el método de síntesis propuesto es adecuado para la obtención, a baja temperatura (700 ºC), de nanopartículas de la fase cristalina y pura del g-LiAlO2. Se discute un posible mecanismo de formación del compuesto de estudio a partir de los geles precursores usados.

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Modifications of micro-pulling-down method for the growth of selected Li-containing crystals for neutron scintillator and VUV scintillation crystals

Cited by 19 publications

References 13 publications

Lu2O3-based storage phosphors. An (in)harmonious family

Lu2O3-based storage phosphors. An (in)harmonious family

Crystal growth and scintillation properties of selected fluoride crystals for VUV scintillators

Nanosized Lithium Aluminate (γ-LiAlO2) Synthesized by EDTA-citrate Complexing Method, Using Different Thermal Conditions

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