【作者】 朱立刚；

【导师】 卢安贤；

【作者基本信息】 中南大学 ， 材料学， 2012， 博士

【摘要】 稀土离子掺杂发光玻璃在激光、光学放大器、光通讯、储能和显示等光电领域有着广泛的应用。氧氟玻璃既具有氧化物玻璃的高机械强度、高化学稳定性和热稳定性等特点,又具有氟化物玻璃声子能低的优点,能有效地提高稀土离子的发光强度。本论文以Sm3+、Dy3+、Ce3+和Tb3+等稀土离子掺杂的SiO2-Al2O3-LiF-CaF2氧氟玻璃为研究对象,对其组成、制备工艺以及热处理对氧氟玻璃性能的影响进行研究,并对玻璃组成-结构-发光性能三者之间的相关性进行了探索。通过大量的实验工作,取得了一些创新性成果。研究了Sm3+、Dy3+、Ce3+和Tb3+等稀土离子掺杂SiO2-Al2O3-LiF-CaF2氧氟玻璃的结构、热稳定性和吸收/透光性能。结果表明,这些氧氟发光玻璃体系的结构主要是[SiO4]四面体和[Al04]四面体以顶角相连的方式构成基本网络骨架,Li+、Ca2+和稀土离子处于网络间隙,Al3+主要作为玻璃网络形成体以[Al04]形式参与网络构成,部分F-取代02-进入网络内部,而另一部分F-则位于网络间隙。玻璃的稳定因子均大于100,表明所制备的玻璃具有较好的热稳定性；玻璃的Hruby常数较高,表明它们具有-定的抗析晶能力。Sm3+、Dy3+离子单掺SiO2-Al2O3-LiF-CaF2氧氟玻璃在紫外-可见-近中红外区具有良好的吸收性能。Ce3+、Tb3+离子单掺／共掺SiO2-Al2O3-LiF-CaF2氧氟玻璃在可见光区具有良好的透光性能,且紫外吸收边较短,有利于发射光的透过。研究了热处理对SiO2-Al2O3-LiF-CaF2氧氟微晶玻璃结构与性能的影响。对基础玻璃进行了晶化处理,计算了玻璃的析晶活化能和晶化指数,并分析了其析晶机理。研究表明,晶化温度控制在670-690℃范围之内,保温时间为2h,可以获得理想的含CaF2单一晶相的透明微晶玻璃。在紫外光的激发下,相比较基础玻璃试样,微晶玻璃试样中的稀土离子可以发出更大强度的荧光。研究了Sm3+、Dy3+离子单掺SiO2-Al2O3-LiF-CaF2氧氟玻璃的荧光性能。在紫外光的激发下,Sm3+离子单掺SiO2-Al2O3-LiF-CaF2氧氟玻璃发射出强烈的橙色光,其发光强度随Sm3+离子掺杂浓度表现出先增大后减小的规律,最佳掺杂浓度为1.0m0l%。Sm3+离子的发光衰减时间为毫秒级,且随Sm3+离子掺杂浓度的增大而减小。Sm3+离子之间的能量转移机制主要为偶极-偶极相互作用。Dy3+离子单掺Si02-Al203-LiF-CaF2氧氟玻璃的蓝色发光4F9/2→6H15/2(482nm)强于黄色发光4F9/2→6H13/2(574nm),成为最强发射,从而提供了独特的更高效率的可供固体激光、光纤放大用的材料基质。Dy3+离子的发光强度随Dy3+的掺杂量表现出先增大后减小的规律,最佳掺杂浓度为0.5mol%。Dy3+离子的发光衰减时间为毫秒级,且随玻璃中Dy3+离子掺杂浓度的增大而减小。Dy3+离子之间的能量转移机制主要为偶极-偶极相互作用。研究了Ce3+、Tb3+单掺/共掺SiO2-Al2O3-LiF-CaF2氧氟玻璃的荧光性能。在紫外光的激发下,Ce3+离子单掺SiO2-Al2O3-LiF-CaF2氧氟玻璃发射出强烈的蓝紫光,发光中心位于385nm附近,其发光衰减时间为纳秒级。Tb3+离子单掺SiO2-Al2O3-LiF-CaF2氧氟玻璃主要表现为绿光发射5D4→7FJ(J=6-3)。其中,543nm附近5D4→7F5绿光发射的相对强度是其它发射峰的2.5倍以上。即使Tb3+离子浓度高达8.0mol%,也没有观察到浓度猝灭现象。说明玻璃基质为稀土离子提供了一个非常均匀的环境,稀土离子得到了相当均匀的分布,减少了稀土离子的非辐射驰豫,提高了其发光强度和荧光猝灭浓度,从而为高密度绿光激光和短光纤放大提供了优质材料。Ce3+/Tb3+离子共掺SiO2-Al2O3-LiF-CaF2氧氟玻璃主要表现为Tb3+离子的绿光发射(主峰位于543nm附近),体系中存在Ce3+→Tb3+的能量转移,导致Tb3+离子的发光强度达到了相同浓度Tb3+离子单掺玻璃样品的10倍以上且Tb3+离子的发光强度随着Ce3+离子浓度的增加表现出先增大后减小的规律。Ce3+-Tb3+离子间的共振能量转移主要表现为电偶极-电偶极的相互耦合作用机制。更多还原

【Abstract】 Rare earth ions doped luminescence glass has a wide range of applications in optoelectronics field, such as laser, optical amplifiers, optical communications, energy storage and display. Oxyfluoride glass has many advantages, including high mechanical strength, excellent chemical stability and thermal stability of oxide glass and lower phonon energy of fluoride glass, which can effectively enhance the luminescence intensity of the doped RE ions. The present paper take Sm3+, Dy3+, Ce3+and Tb3+doped SiO2-Al2O3-LiF-CaF2oxyfluoride glass as the research object, its composition and preparation process, as well as the effect of heat treatment on the performance of oxyfluoride glass has been studied in detail, and the relationship between glass composition, structure, and luminescent properties has been explored.Through substantive experimental work, some new and interesting results have been obtained and listed as follows.The structure, thermal stability, and absorption or transmittance performance of Sm3+, Dy3+, Ce3+and Tb3+doped SiO2-Al2O3-LiF-CaF2oxyfluoride glass have been investigated. The results indicated that the network of these oxyfluoride luminescent glasses is composed mainly of [SiO4] and [AlO4] tetrahedrals, which linking by vertex angle oxide ions. Li+, Ca2+and/or the RE ions are in the network gap, Al3+ions mainly as the glass network former enter in the network with [AlO4] tetrahedrals, part F-ions substitute for O2-ions to enter in the network, and another part located at the network gap. The glass stability factors all greater than100, indicating that these oxyfluoride luminescent glasses have good thermal stability, and the glass Hruby constants indicated that they have certain anti-crystallization ability. The Sm3+, Dy3+single doped SiO2-Al2O3-LiF-CaF2oxyfluoride glass has a good absorption property in the UV-vis-NIR region, whereas Ce3+, Tb3+ions single doped or codoped oxyfluoride glass has a good light transmittance performance in the visible region, and the UV absorption edge is shorter, which is advantageous for the transmission of emission light. The effect of heat treatment on the structure and properties of SiO2-Al2O3-LiF-CaF2oxyfluoride glass-ceramic has been investigated. The crystallization treatment has been carried out on the as-made glass, the crystallization activation energy and crystallization index have been calculated, and the crystallization mechanism has been analyzed. The results indicated that it can be obtain an ideal only containing CaF2nanocrystalline transparent glass-ceramic by controlled the crystallization temperature within the range of670-690℃, and the holding time of2hours. Compare to the as-made glass, the RE ions in glass-ceramic exhibit greater intensity fluorescence under UV excitation.The luminescent property of Sm3+or Dy3+doped SiO2-Al2O3-LiF-CaF2oxyfluoride glass has been investigated. The Sm3+doped SiO2-Al2O3-LiF-CaF2oxyfluoride glass emits intense orange light under UV excitation, and the luminescent intensity first increases and then decreases with the optimal Sm3+concentration of1.0mol%. The luminescence decay time of Sm3+is of milliseconds magnitude, with the Sm3+increasing concentration decreases. The main energy transfer mechanism between Sm3+-Sm3+ions is the dipole-dipole interaction. The blue light-emitting4F9/2→6H15/2(482nm) of Dy3+ions doped SiO2-Al2O3-LiF-CaF2oxyfluoride glass is stronger than the intensity of yellow light-emitting4F9/2→6H13/2(574nm) under UV excitation, and becomes the strongest emission. Thus, the Dy3+ions doped oxyfluoride luminescent glass providing a unique and more efficient material matrix for the solid-state laser and fiber amplifier. The luminescent intensity of Dy3+ions doped oxyfluoride luminescent glass first increases and then decreases with the optimal Dy3+concentration of0.5mol%. The luminescence decay time of Dy3+is of milliseconds magnitude, and with the Dy3+increasing concentration decreases. The main energy transfer mechanism between Dy3+-Dy3+ions is the dipole-dipole interaction.The Ce3+doped SiO2-Al2O3-LiF-CaF2oxyfluoride glass emits intense purplish-blue light under UV excitation, luminescence centers at385nm with the luminescence decay time of the order of nanoseconds. The Tb3+doped SiO2-Al2O3-LiF-CaF2oxyfluoride glass mainly emits the green emissions5D4→7FJ(J=6-3). Of them, the relative intensity of 543nm (5D4→7F5) green emission is above2.5times than other emissions. It is very significant that Tb3+can be doped up to8.0mol%in host glass without concentration quenching. This indicates that the as-made host glass provides a more homogeneous environment, and enhances the distribution of RE ions. The good distribution of RE ions could reduce the non-radiative relaxation, and result in an increase in the emission intensity and quenching concentration. Therefore, the as-made Tb3+doped oxyfluoride luminescent glass has important potential applications in the high-density green laser and short fiber amplifier. Ce3+/Tb3+codoped SiO2-Al2O3-LiF-CaF2oxyfluoride glass mainly exhibits the green emission of Tb3+ions (peak at543nm) under UV excitation. The Ce3+→Tb3+effective energy transfer were observed in Ce3+/Tb3+codoped oxyfluoride luminescent glass, resulting in the luminescent intensity of Tb3+enhances above10times than that of the same Tb3+concentration single doped oxyfluoride glass. It was also observed that the luminescent intensity of Tb3+in Ce3+/Tb3+codoped oxyfluoride luminescent glass increases firstly and then decreases with the increasing Ce3+ions concentration. The main resonance energy transfer mechanism between Ce+-Tb3+ions is the dipole-dipole interaction.更多还原