本文選題：氟化鈣 + 釹��； 參考：《武漢理工大學(xué)》2015年碩士論文

【摘要】：納米材料在一維空間具有小尺寸,微晶由表面原子數(shù)目以及電子態(tài)的量子約束所影響,從而引起了不同于一般材料所具有的新穎性質(zhì),特別是在熒光材料方面,因其發(fā)射壽命、熒光量子效率以及濃度猝滅都強(qiáng)烈依賴于粒子的尺寸。CaF2由于其穩(wěn)定性及非吸濕性成為最具吸引力的氟化物材料,目前有很多關(guān)于稀土摻雜氟化物的合成和性能研究,尤其在激光器研究方面。Nd3+離子具有很寬的吸收帶,泵浦閾值低、吸收和發(fā)射截面都較大,是一種性能優(yōu)良的增益介質(zhì)。在激光應(yīng)用方面,Nd3+離子是最早且最廣的,已經(jīng)可作為100多種基質(zhì)材料的激活離子。Nd3+離子在808nm附近具有較大的吸收,可實(shí)現(xiàn)1064nm波長(zhǎng)激光輸出,共摻Y(jié)3+離子可以形成[Nd3+-Y3+]激活中心,并能取代原有的[Nd3+-Nd3+]團(tuán)簇體結(jié)構(gòu),由于[Nd3+-Y3+]團(tuán)簇體的結(jié)構(gòu)更為復(fù)雜,在晶體中產(chǎn)生了豐富的多格位,從而能夠降低或防止稀土離子和某些交叉弛豫引起的能量轉(zhuǎn)移而產(chǎn)生的濃度淬滅效應(yīng),因而對(duì)光學(xué)性能的提高有較明顯的作用,能夠增加發(fā)射線寬并能在1.06μm處實(shí)現(xiàn)連續(xù)波運(yùn)轉(zhuǎn)。本文采用化學(xué)沉淀法合成并采用兩種干燥方法制得Nd,Y:CaF2納米粉體,主要探索不同的反應(yīng)因素對(duì)制備粉體結(jié)構(gòu)和性能的作用。本研究所采用的方法、研究的內(nèi)容和結(jié)果分析表現(xiàn)如下:1.選擇化學(xué)沉淀法合成了Nd,Y:CaF2納米粉體,并利用X射線衍射儀、場(chǎng)發(fā)射掃描電鏡、粒度分析儀、紅外光譜儀、吸收光譜儀等測(cè)試手段探索了Nd,Y:CaF2納米粉體的晶格結(jié)構(gòu)、形貌、分散性、粒度分布以及光學(xué)性能的影響。研究結(jié)果發(fā)現(xiàn),所獲得粉體形貌近似成球形,晶粒尺寸在18-25nm范圍內(nèi),分散性較好,結(jié)晶較好,存在雜質(zhì)離子。2.分別研究不同Nd,Y摻雜含量對(duì)CaF2納米粉體的影響,當(dāng)固定Y3+摻雜為2at%時(shí),Nd3+的摻雜為4 at%時(shí)的顆粒分散性最好、粒度分布最窄。隨著Y3+摻雜量的增加,晶胞參數(shù)增加,半高寬也逐漸增加,說明結(jié)晶度降低,晶格缺陷增加。ICP結(jié)果表明,2%Nd,4%Y:CaF2樣品Nd3+離子的實(shí)際摻雜摩爾百分?jǐn)?shù)為1.98%,Y3+離子的實(shí)際摻雜摩爾百分?jǐn)?shù)3.78%,說明稀土離子很好地?fù)竭M(jìn)到了CaF2晶格中。3.研究了不同燒結(jié)溫度對(duì)合成的Nd,Y:CaF2納米粉體的結(jié)構(gòu)及性能影響,低溫(200℃)煅燒時(shí),晶粒尺寸變化不大,當(dāng)溫度繼續(xù)升高時(shí),顆粒逐漸長(zhǎng)大,形貌邊界更加清晰,雜質(zhì)離子的去除效果也更好,吸收強(qiáng)度基本呈上升到趨勢(shì),但是溫度達(dá)到800℃時(shí),吸收強(qiáng)度反而大幅度下降且對(duì)雜質(zhì)離子的排除同600℃相比基本沒有多大變化。綜合考慮一次粒徑和雜質(zhì)的去除情況,600℃是較好的煅燒溫度。4.由于濕凝膠在干燥過程中容易橋接粘連而發(fā)生團(tuán)簇,通過改進(jìn)工藝,在干燥之前采用正丁醇作為共沸劑進(jìn)行共沸蒸餾使凝膠中的水分最大限度被去除。共沸蒸餾法獲得的粉體團(tuán)聚程度明顯減輕,粒度分布均勻,TG-DSC、FTIR以及吸收光譜均表明其脫水效果比直接干燥法更佳。
[Abstract]:Nanomaterials have small size in one-dimensional space, and the microcrystals are influenced by the number of atoms on the surface and the quantum confinement of electronic states, which leads to novel properties different from those of common materials, especially in fluorescent materials, because of their emission lifetime. Fluorescence quantum efficiency and concentration quenching are strongly dependent on particle size. CaF2 is the most attractive fluorine material due to its stability and non-hygroscopicity. There are many studies on the synthesis and properties of rare-earth doped fluorides. Especially in laser research. Nd3 ion has a wide absorption band, low pump threshold, large absorption and emission cross sections, and is a good gain medium. Nd3 ion is the earliest and most widely used in laser application. It can be used as activator ion. Nd3 ion of more than 100 kinds of matrix material can be absorbed in the vicinity of 808nm, and the laser output of 1064nm wavelength can be realized. Co-doped Y3 ions can form [Nd3 -Y3] activation center and replace the original [Nd3 -Nd3] cluster structure. Because the structure of [Nd3 -Y3] cluster is more complex, there are abundant multi-lattice sites in the crystal. It can reduce or prevent the concentration quenching effect caused by the energy transfer caused by rare earth ions and some cross relaxation, so it can obviously improve the optical properties, increase the emission linewidth and realize the continuous wave operation at 1.06 渭 m. The nanocrystalline ND: y: CaF2 powder was prepared by chemical precipitation and two drying methods. The effects of different reaction factors on the structure and properties of the prepared powder were investigated. The methods, contents and results of this study are as follows: 1. The nanocrystalline ND: y: CaF2 powder was synthesized by chemical precipitation method. The lattice structure, morphology and dispersibility of ND: y: CaF2 nanocrystalline powder were investigated by means of X-ray diffractometer, field emission scanning electron microscope, particle size analyzer, infrared spectrometer and absorption spectrometer. The effect of particle size distribution and optical properties. The results show that the morphology of the powder is approximately spherical, the grain size is in the range of 18-25nm, the dispersion is better, the crystal is better, and the impurity ion. 2. The effect of different NdCY doping content on CaF2 nano-powders was studied. When the doping of Y3 was 2at%, the dispersion of Nd3 particles was the best and the particle size distribution was narrowest when the doping content of Nd3 was 4at%. With the increase of Y3 doping amount, the crystal cell parameters and the half-maximum width increase gradually, which indicates that the crystallinity decreases. The results of lattice defect increase. ICP results show that the actual doped mole percentage of Nd3 ion in the sample of ND: CaF2 is 1.98% and 3.78 mol% of Y3 ion, which indicates that rare earth ions are well doped into CaF2 lattice. 3. The effect of sintering temperature on the structure and properties of the synthesized ND: y: CaF2 nano-powder was studied. The grain size changed little when calcined at low temperature (200 鈩，

本文編號(hào)：1980763