利用共沉淀法制备超细YAG粉体及其表征

钇铝石榴石(YAG)具有稳定的化学性能,在作为化工新型材料使用中得到了广泛应用。本文通过利用共沉淀法制备超细YAG粉体。通过研究可以得到,前驱体在1100℃下煅烧1h后,生成了纯的YAG晶体。合成的YAG颗粒比较分散、细小,其粒度大小相当均一,粉体颗粒粒径在200～350nm之间,其颗粒近似球形,颗粒之间有部分烧结现象出现。     

钇铝石榴石粉体制备技术的研究进展

本文对钇铝石榴石粉体制备技术的研究现状做了系统的概述,着重介绍了目前在YAG粉体的制备中应用较多的固相法、溶胶-凝胶法、溶剂（水）热法和共沉淀法等几种方法．简要地分析了这几种方法在YAG粉体制备中的优缺点,指出了共沉淀法是现阶段最具潜力的一种合成方法。     

纳米尖晶石型复合氧化物的合成及应用

本文综述了纳米尖晶石型复合氧化物的合成方法，包括物理合成法和化学合成法。主要介绍了化学合成法，如：沉淀法（直接沉淀法，均相沉淀法，共沉淀法），溶胶－凝胶法，水热法，化学气相沉积法和微孔液法，并比较了不同合成方法的优缺点。同时介绍了纳米尖晶石型复合氧化物的应用现状，发展前景，它可以作为颜料，磁性材料，催化材料，隐身材料等广泛应用于生产和生活的各领域中，是一类重要的无机材料。     

湿化学法制备高性能PTC粉体的研究

采用草酸盐共沉淀法和柠檬酸盐溶胶-凝胶二步合成法两种湿化学法合成了高性能的PTC粉体。草酸盐共沉淀法制备的PTC粉体平均粒径为200nm，粉体部分团聚；柠檬酸盐溶胶-凝胶二步合成法得到了纳米级的PTC粉体，平均粒径为70nm，粒度分布均匀，分散性较好。讨论并分析比较了两种合成方法的粉体形成历程、机理和微观形貌，两种方法比较，后者所得粉体化学组成更为均匀、晶型发育更为完全。     

激光材料专用YAG粉体制备技术研究进展

本文对国内外目前激光材料专用的YAG粉体制备技术现状做了系统概述。重点介绍了目前YAG粉体制备的几种方法;固相反应法,气相化学法.沉淀法,溶剂热法,溶胶-凝胶法等:并对各种方法的优缺点做了对比:指出以钇铝醇盐为原料,以溶胶-凝胶法为基础制备YAG粉体是最具产业潜力的方法.     

胶束辅助的共沉淀法制备YAG：Eu纳米粉体及其发光性能

以CTAB为表面活性剂,乙醇、正丁醇为CTAB的增溶剂,采用胶束辅助的共沉淀法制备了YAG：Eu前驱体。在空气气氛中,分别在900℃、1000℃下烧结2h得到YAG：Eu粉体。应用XRD、TEM和光致发光等方法对试样进行了表征。结果表明：在900℃、1000℃烧结前驱体可合成立方相YAG：Eu;YAG：Eu颗粒大小在50～70nm之间,团聚成珊瑚虫形;YAG：Eu粉体发射橙红色光。     

稀土掺杂YAG荧光粉制备方法的研究进展

概述了稀土掺杂钇铝石榴石(YAG)荧光材料的研究进展,着重介绍了YAG荧光粉的制备方法,如:高温固相反应法、溶胶-凝胶法、共沉淀法等。同时简单介绍了其应用和目前生产和应用中存在的问题。指出微波均相法是制备YAG荧光粉的一种新方法;粉体的表面修饰是提高荧光粉体性能的有效途径。     

一步共沉淀法合成钇铝石榴石纳米粉体

以Ai（NO3）y9H20和Y（NO3）3-6H20为原料,NH4HCO3为沉淀剂,十二烷基苯磺酸（C18H30SO3）为分散剂,采用一步共沉淀法合成钇铝石榴石（Y3A15O12,YAG）纳米粉体。利用X射线衍射仪、Fourier红外光谱仪、同步热分析仪和场发射扫描电子显微镜对YAG前驱体及不同温度煅烧后的粉体进行表征。结果表明：YAG前驱体化学组成为10[Al（Oh）3]·3[Y2（CO3）3＋3H2O],900℃煅烧2h后转变为纯YAG相,1000℃煅烧2h后得到的粉体晶型完整、分散性好、颗粒尺寸分布均匀,形状近似球形,平均粒径约为65nm。该方法较传统共沉淀法操作步骤简化、参量减少、可重复性提高,因此,更有利于实现工业化批量生产。     

超细钛酸钡粉体湿化学合成技术

近十年来，钛酸钡粉体的合成技术发展十分迅速。其中，超细钛酸钡粉体的湿化学合成技术倍受关注，主要包括溶胶-凝胶、溶胶-沉淀、燃烧合成、化学共沉淀和水热合成等多种方法。简要综述了这5种主要的湿化学合成工艺，并重点分析了溶胶-凝胶法等制备钛酸钡粉体过程中各种因素对粉体的粒径和形态的影响。     

不同粉体制备工艺对Ca3Co4O9陶瓷性能的影响

采用溶胶凝胶法和化学共沉淀法制备了Ca3Co4O9粉体,并烧结为纯相Ca3Co4O9陶瓷。利用XRD、SEM等方法对陶瓷样品的物相以及断面形貌进行了表征,利用四探针法测量了Ca3Co4O9陶瓷的电导率。试验结果表明化学共沉淀法与溶胶凝胶法粉体相比,制得的Ca3Co4O9陶瓷不仅具有更低的气孔率、线收缩率,而且具有更高的电导率,也是一种制备高性能热电材料粉体的有效方法。     

Rapid synthesis of YAG phosphor by facile mechanical method

In this study, synthesis of yttrium aluminum garnet (YAG):Ce³⁺ phosphor powders for white light emitting diodes was investigated by mechanical method using the attrition-type mill with no external heating and no flux in dry phase. High mechanical energy input to the starting powder mixture of Y₂O₃, Al₂O₃ and CeO₂ achieved the synthesis of YAG:Ce³⁺ without any flux materials. X-ray diffraction patterns of the processed powders after 5 min processing revealed the peaks of YAG were clearly identified. The maximum temperature of the mill chamber during the processing was 240℃. The YAG phosphor obtained by the mechanical method revealed the internal quantum yield of 65% in the case of the sample mechanically processed under a reducing atmosphere. The synthesized powder showed granule structure consisting of submicron size of YAG particles, which is better handling for the fabrication of light emitting diode devices.     

Synthesis of Nd:YAG powders leading to transparent ceramics: The effect of MgO dopant

Neodymium doped yttrium aluminum garnet (Nd:YAG) ultrafine powders were synthesized by co-precipitation method using MgO as dopant. The addition of small amount of MgO can reduce the agglomeration and particle size of the produced Nd:YAG powders. The results show that pure phase YAG powders can be achieved by calcining of the precursors at 1000 °C for 2 h. The MgO doped Nd:YAG powders show better dispersion compared with the undoped powders. When the MgO content is 0.01 wt.%, well-dispersed Nd:YAG powders with spherical particles of 100 nm diameter were obtained. The transmission of the corresponding Nd:YAG ceramics is 82.6% at the wavelength of 1064 nm, which is comparable to Nd:YAG single crystals.     

The study of surfactant application on synthesis of YAG nano-sized powders

Yttrium aluminum garnet (YAG) nano-sized powders were synthesized using the co-precipitation method with ammonium hydrogen carbonate as precipitant, nonionic, anionic and cationic surfactant as dispersant, respectively. The composition of YAG precursor, the phase formation process of YAG and the properties of the powders were investigated by means of IR, XRD and TEM. The results show that the anionic surfactant is beneficial for the dispersion of the resulting YAG powders. Highly crystalline, well-dispersed nano-sized YAG crystallites were obtained by calcining at 1000 °C for 2 h in the presence of the anionic surfactant. The average size of the particle is about 30 nm. Luminescence properties of the Nd-doped YAG powders prepared with surfactant and with no surfactant were also studied.     

钇铝石榴石(YAG)激光透明陶瓷研究进展

钇铝石榴石(YAG)激光透明陶瓷由于具有单晶、玻璃激光材料无可比拟的优势而成为研究热点,并得到迅速发展,高性能的稀土元素掺杂YAG透明激光陶瓷被相继报导.本文综述了近年来国内外关于YAG激光透明陶瓷的最新研究成果.主要包括YAG微细粉体合成、烧结添加刺及多晶YAG透明陶瓷的致密化烧结技术,并对比了YAG透明陶瓷相对于Y...     

Influence of powder physicochemical characteristics on microstructural and optical aspects of YAG and Er:YAG ceramics obtained by SPS

The present work aims to establish a correlation between the characteristics of YAG and Er:YAG commercial powders produced by two different synthesis routes and sintered ceramic microstructures and their optical aspect by taking into account the influence of pressure applied during the Spark Plasma Sintering (SPS) process. Physical and chemical characteristics of the powders were compared using various techniques such as SEM, XRD, laser diffraction and chemical analyses. Their behaviours were evaluated through a rheological study, compressibility tests and dilatometry cycles using SPS. This paper pinpoints the most important powder features which influence the optical quality of YAG and Er:YAG ceramics. The optical quality is mainly affected by the porosity, related to powder characteristics that affect particle rearrangement, densification and grain growth. The applied pressure induces microstructural heterogeneities depending on the starting material used and resulting in core-shell aspects of sintered ceramics.     

A comparative study of synthesis and spark plasma sintering of YAG nano powders by different co-precipitation methods

Pure yttrium-aluminum-garnet (YAG) nano particles were synthesized via normal and reverse co-precipitation methods using nitrate starting solutions and ammonium hydrogen carbonate (AHC) as precipitator agent. The impact of titration method on the phase evolution, thermal behavior, precipitate's composition, morphology and chemical bonds of powders were studied by XRD, TG-DTA, FTIR, FESEM, TEM, EDS and BET analysis. The results revealed that in the normal method, the precipitates were composed of relatively dense particles compared with more homogenous fluffy precipitates with higher carbonate content obtained by the reverse method. The precursors achieved by the reverse method formed less agglomerated and smaller size YAG powders after calcination at 900?°C. Calcined nano powders were processed by spark plasma sintering (SPS) technique at 1350?°C for 10?min without any sintering aids or dispersive agents. The sintering of both powders led to a highly dense and fine submicron-structured YAG ceramic. However, the YAG ceramic produced by SPS of reverse co-precipitated nano powders showed higher transparency (43% at 680?nm and 58% in near-infrared range) and finer micro-structure (about 210?nm in grain size) as compared with normal co-precipitated nano particles.     

YAG纳米粉体的制备技术研究进展

近年来YAG纳米粉体因其具有特殊的性能而备受人们的关注。以此为原料采用先进的陶瓷制备工艺可以得到透明的YAG固体激光工作介质 ,其物理化学及光学性能可与单晶相比拟。YAG粉体通过掺杂Ce3 ,Tb3 ,Eu3 等离子还可以作为超短余辉荧光粉 ,在发光材料领域有广泛的应用。本文着重介绍了目前应用较多的几种YAG纳米粉体的制备方法 ,并简要地比较了各种方法的优劣。