磁光玻璃的制备及光谱性能研究

发布时间：2018-03-15 02:00

本文选题：磁光玻璃　切入点：发光性能　出处：《陕西科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：本课题采用熔融法制备了高Verdet常数的Ge O2-B2O3-Si O2-Tb2O3(GBST)磁光玻璃,采用光学碱度、光学带隙、稀土光谱理论等探究了磁光玻璃基本物理性能、结构、光谱性能等,并探究了磁场及不同球磨方法对磁光玻璃发光性能的影响,主要研究结论如下:(1)随着Tb2O3含量的增加,磁光玻璃的密度呈抛物线性增加,Verdet常数线性增加,且在Tb2O3含量为70 mol.%时为时密度和Verdet常数分别为6.248 g/cm3和-0.50 min/Oe·cm。光学碱度和氧离子极化率随Tb2O3摩尔含量的增加而增大,高的光学碱度导致Tb3+离子的5d能级分裂加大,增加了磁光玻璃的磁矩和氧离子极化率,导致Verdet常数的加大;(2)GBST磁光玻璃试样在Tb2O3含量为10 mol.%时稳定性最高,析晶倾向最低。经过析晶处理后可以得到Tb BO3晶体。含Tb3+离子的GBST磁光的网络结构是由[Si O4]、[BO3]和[BO4]等混合而成的,且玻璃中存在偏硼酸盐形成大的无穷链状结构,Tb3+填充在其中的两个硼氧三角体[BO3]和一个硼氧四面体[BO4]之间的空隙中;(3)随着Tb2O3摩尔含量的增加,磁光玻璃的吸收边增加,光学带隙降低,但他们变化的幅度不大。Tb3+离子的极化率较低,但其轨道能与O2-离子形成具有较大极化率的基团,电子云容易发生变形。随着Tb3+离子的加入,非桥氧增加,玻璃的光学带隙都减小;(4)GBST磁光玻璃的激发强度、发射强度及荧光寿命都随着Tb2O3摩尔含量的增加呈现先增加后降低的趋势,且在Tb2O3为10 mol.%时达到最大。(5D3,7F6)→(5D4,7F0)交叉弛豫是导致浓度猝灭的主要原因。热处理后磁光玻璃试样的发光强度增大,主要原因为形成微晶后,基质的声子能量降低,Tb3+在晶体场的作用下,降低了电子由高能级向低能级弛豫的几率,使得高能级上的电子布局数增加;(5)引入磁场后,磁光玻璃的发光强度降低,Tb2O3含量与发光强度降低量关系不大,与磁光玻璃自身发光强度有关。即发光强度高的磁光玻璃,引入磁场后,发光强度降低量大。当磁光玻璃粉的粒度降低后,其发光强度降低。在相同粒度下,湿磨工艺比干磨得到的荧光粉发光强度小,在实际应用过程中,要获得较好的发光性能,磁光玻璃粉应采用干磨工艺,颗粒尺寸应适当,结合激发条件、以及使用场合,来确定其大小。磁光玻璃粉体粒度越小,其相对比表面积越大,导致缺陷和猝灭中心的增加,降低了发光强度,此外水中的-OH与玻璃发生反应,使磁光玻璃粉表面的悬键变多,表面缺陷变多,导致荧光淬灭。
[Abstract]:The magneto-optic glass with high Verdet constant, GE O 2-B 2O 3-Si O 2-TB 2O 3 GST, was prepared by melting method. The basic physical properties, structure and spectral properties of magneto-optic glass were investigated by optical basicity, optical band gap and rare earth spectrum theory. The effects of magnetic field and different ball milling methods on the luminescence properties of magneto-optic glass are investigated. The main conclusions are as follows: 1) with the increase of Tb2O3 content, the density of magneto-optic glass increases linearly with parabola. When the content of Tb2O3 is 70 mol 路%, the duration density and Verdet constant are 6.248 g / cm ~ 3 and -0.50 min/Oe 路cm ~ (-1), respectively. The optical basicity and oxygen ion polarizability increase with the increase of Tb2O3 molar content, and the high optical basicity leads to the splitting of 5-day energy level of Tb3 ion. The magnetic moment and oxygen ion polarizability of magneto-optic glass were increased, which resulted in the highest stability of the magneto-optic glass sample when the Tb2O3 content was 10 mol 路%. After crystallization treatment, TB BO3 crystal can be obtained. The network structure of GBST containing Tb3 ion is composed of [Sio _ 4], [BO3] and [BO4]. Moreover, there are two boron triangles [BO3] and a boron tetrahedron [BO4] in which there is a large infinite chain structure formed by metaborates. The absorption edge of magneto-optic glass increases with the increase of Tb2O3 molar content. The optical band gap is decreased, but the polarizability of Tb3 ion is small. However, its orbital energy and O _ 2-ion form a group with large polarizability, and the electron cloud is prone to deform. With the addition of Tb3 ion, the non-bridged oxygen increases. The optical band gap of the glass decreases the excitation intensity, the emission intensity and the fluorescence lifetime of the glass increase first and then decrease with the increase of the molar content of Tb2O3, and reach the maximum value of .5D3O7F6 when the Tb2O3 is 10 mol 路%. 鈫扐fter heat treatment, the luminescence intensity of magneto-optic glass increased, the main reason was that the phonon energy of the matrix decreased under the action of crystal field. The probability of electron relaxation from high energy level to low energy level is reduced, and the number of electron configurations at high energy level increases by 5). When magnetic field is introduced, the decrease of luminescence intensity of magneto-optic glass is not related to the decrease of luminescence intensity. It is related to the luminescence intensity of magneto-optic glass, that is, the magneto-optic glass with high luminescence intensity decreases greatly with the introduction of magnetic field. When the particle size of magneto-optic glass decreases, its luminescence intensity decreases. The luminous intensity of phosphor produced by wet grinding is smaller than that by dry grinding. In order to obtain better luminous properties in practical application, the magneto-optic glass powder should adopt dry grinding technology, the particle size should be appropriate, and the excitation conditions should be combined, as well as the application situation. The smaller the granularity of magneto-optic glass powder, the larger its relative specific surface area, which leads to the increase of defect and quenching center, and decreases the luminescence intensity. In addition, the -OH in water reacts with glass, resulting in more hanging bonds on the surface of magneto-optic glass powder. More surface defects lead to fluorescence quenching.
【学位授予单位】：陕西科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ171.79

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