本文選題：鈮酸鋰　切入點：納米線　出處：《浙江大學》2010年碩士論文

【摘要】： 鈮酸鋰(LiNbO_3)是一種具有很高居里溫度和很大自發(fā)極化強度的鐵電體氧化物材料,其本身也具有良好的電光、壓電和非線性光學等性能,因此在聲表面波傳感器、光通訊、濾波器等領域大顯身手,被稱為“聰明”和“通用型”晶體。鈮酸鋰除了不能做光源探測器以外,適合制作光的多種控制耦合和傳輸器件,例如:光調(diào)制、光波導、光放大、光隔離等器件。納米線、納米顆粒,由于量子限制效應所具有的優(yōu)異的電學和光學性質(zhì),在電、光器件方面展示出誘人的前景,但是目前鈮酸鋰器件還停留使用體單晶、薄膜材料微電子工藝上,隨著微電子向納電子技術的發(fā)展,LiNbO_3材料也要向納米材料制備方向發(fā)展,因此納米結(jié)構鈮酸鋰的研究對我國可持續(xù)發(fā)展有重要的意義。 本文以五氧化二鈮、一水氫氧化鋰和氫氧化鉀為原料,在自制的水熱反應釜中利用水熱法成功制備了多種鈮酸鋰微/納米結(jié)構。 反應體系中不加入任何基底情況下,在保證三種藥品的摩爾比為:Nb_2O_5:LiOH·H_2O:KOH=1:2:11條件下,改變反應物的濃度,分別制備了鈮酸鋰微/納米顆粒和層狀鈮酸鋰納米結(jié)構;如果反應體系加入表面活性劑聚乙烯吡咯烷酮,在活性劑含量為0.04g～0.02g之間時制備出了鈮酸鋰納米管陣列。 反應體系中放置多晶氧化鋁基底時,我們制備了化學計量比鈮酸鋰微/納米線。為了了解水熱法制備鈮酸鋰微/納米線的生長機理,我們分別對反應時間、反應溫度、反應物濃度、襯底的作用和氫氧化鉀對實驗的影響等進行了深入而細致的分析,獲得了優(yōu)化的生長條件。最佳生長條件是:反應物Nb_2O_5、LiOH·H_2O、KOH的含量分別為0.2g、0.063g、0.464g(Nb_2O_5:LiOH·H_2O:KOH=1:2:11),反應溫度為150℃,反應時間為5天。XRD、SEM和HRTEM測試表明:我們所制備的鈮酸鋰微/納米線為四方形貌,長度達幾十微米,生長方向為[110]。 我們對生成的鈮酸鋰微/納米線進行了光波導性能研究,發(fā)現(xiàn)退火可以使其光波導性能非常優(yōu)異。并且我們也研究了不同角度下耦合光對其性能的影響。實驗中,我們發(fā)現(xiàn)鈮酸鋰對紅外(1064nm),紅光(650nm)和綠光(532nm)都有很好的波導性能。
[Abstract]:LiNbO3) is a kind of ferroelectric oxide material with high Curie temperature and high spontaneous polarization. It also has good electro-optic, piezoelectric and nonlinear optical properties, so it is used in surface acoustic wave sensors and optical communication. Filters and other fields are known as "smart" and "general-purpose" crystals. In addition to not being able to be light source detectors, lithium niobate is suitable for making a variety of control coupling and transmitter components for light, such as light modulation, optical waveguide, optical amplification, Optical isolation and other devices. Nanowires, nanocrystals, due to their excellent electrical and optical properties due to quantum confinement effects, have shown attractive prospects in electrical and optical devices, but at present lithium niobate devices still remain in bulk single crystals. In the microelectronic process of thin film materials, with the development of microelectronics to nano-electronic technology, LiNbO3 materials will also be developed towards nanomaterials. Therefore, the study of nanostructured lithium niobate is of great significance to the sustainable development of China. In this paper, a variety of lithium niobate microstructures / nanostructures were prepared by hydrothermal method using niobium pentoxide, lithium hydroxide monohydrate and potassium hydroxide as raw materials. Under the condition that the molar ratio of the three drugs is guaranteed to be 1: Nb2O5: LiOH H_2O:KOH=1:2:11, the lithium niobate microparticles and layered lithium niobate nanostructures are prepared by changing the concentration of the reactants without adding any substrates in the reaction system. If the surfactant polyvinylpyrrolidone is added to the reaction system, the lithium niobate nanotube array is prepared when the surfactant content is 0.04g~0.02g. In order to understand the growth mechanism of lithium niobate microwires / nanowires prepared by hydrothermal method, we prepared stoichiometric lithium niobate microwires / nanowires by placing polycrystalline alumina substrates in the reaction system. The concentration of reactants, the effect of substrate and the effect of potassium hydroxide on the experiment were analyzed in detail, and the optimized growth conditions were obtained. The optimum growth conditions were as follows: the content of Nb2O5 LiH2O5OH, LiH2OKoh, and Koh was 0.2g / t 0.063g / t 0.464g / g, respectively, and the reaction temperature was 150 鈩，

本文編號：1679022