LUMINESCENCE CENTERS OF Eu~(2 ) IN KCaF_3:Eu~(2 )

The nature of the emission center of Eu~(2 ) in KCaF_3:Eu~(2 ) strongly depends on the preparative condi-tions.Experimental results show that there are two different d→f transition emission bands,and the origin ofthese two emission bands,their interrelationship and the effect of doping concentration on them have been dis-cussed.A Eu~(2 )-Eu~(3 ) valency change process has been proposed.     

红外变可见上转换材料薄膜

将ＢａＹＦ５：Ｙｂ，Ｅｒ上转换材料与聚乙烯共混制成一种透光性好、不会脱落、使用和携带方便的高效红外变可见上转换材料薄膜。已用于钕激光器和０．９μｍ半导体激光器的显示。     

含稀土的半导体激光显示材料

输出0.9μ激光的砷化镓半导体激光器是一小型简易,价格便宜的激光器,它已在军用上和医疗上得到应用。收到了较好的效果。但是0.9μ激光是在红外波段,人眼看不到,这给激光的操作和使用带来了困难,近红外光的探测和显示可应用红外变相管来实现,可它的价格较贵,又需一定大小的装置,使用很不方便,且需上万伏的高压     

掺Ce~（3＋）、Tb~（3＋）的四硼酸铝钇的发光特性

本文采用固相反应法合成了一系列掺Ｃｅ￣（３＋）、Ｔｂ￣（３＋）的四硼酸铝钇（Ｙ＿（１－ｘ－ｙ）Ｃｅ＿ｘＴｂ＿ｙＡｌ（ＢＯ＿３）＿４）磷光体。测定了它们的结构、属于三方晶系、空间群Ｒ＿（３２）、Ｌｎ￣（３＋）离子处于六个氧形成的三棱柱中。测定了磷光体中Ｃｅ￣（３＋）、Ｔｂ￣（３＋）和Ｃｅ￣（３＋）－Ｔｂ￣（３＋）共掺时的光谱，观察到Ｃｅ￣（３＋）、的Ｓｔｏｋｅｓ位移相当小（～１７００ｃｍ￣（－１））、Ｔｂ￣（３＋）的能级劈裂较明显和Ｃｅ￣（３＋）能将能量传递给Ｔｂ￣（３＋），测定了磷光体中Ｃｅ￣（３＋）、的荧光寿命，探讨了Ｃｅ￣（３＋）－Ｃｅ￣（３＋）之间的能量传递。     

Y_2O_3稳定的ZrO_2超微粉末的合成与结构研究

本文以水解法、沉淀法,水热法等三种方法制备了Y_2O_3稳定的ZrO_2超微粉末(UFP),对三种化学方法作了综合比较,并确定了制备Y_2O_3稳定的ZrO_2UFP工艺流程。作者认为,水解法较为适宜,在800℃灼烧,粒度较小,结晶度较高。透射电镜观测到该法合成的粉末粒度<0.1μm,XRD分析结果证明Y_2O_3稳定的ZrO_2UFP属立方晶系。     

掺Ce~(3+)、Tb~(3+)的稀土硼酸盐磷光体的合成和发光特性

一、引言硼酸盐体系发光材料的主要特点是灼烧温度低,合成简便、并易于获得高亮度的磷光体。Ce~(3+)激活的稀土硼酸盐的发光,Ce~(3+)—Eu~(2+)激活的卤硼酸盐磷光体以及     

Eu~(2+)激活的钡镁多铝酸盐磷光体的合成

本文试验了合成BaMg_2Al_(16)O_(27):Eu~(2+)的一些主要因素如灼烧温度,一些化学组分改变的影响。试验表明,提高灼烧温度有利于产物发光,但灼烧温度高于1340℃发光亮度不再增加,合适的Eu~(2+)掺入浓度在0·12～0·18克原子范围。Mg~(2+)量和配方中F量的不同对发光亮度、萤光光谱、色纯度和粒度均有影响,通过试验得到了较适宜的BaMg_2Al_(16)O_(27):Eu~(2+)磷光体的制备条件。     

SPECTRAL VARIATION AND CHARACTERISTICS OF LOW VALENCY RARE EARTH IONS IN COMPLEX OXIDESⅢ.EFFECT OF THE CRYSTAL ENVIRONMENT AND CHEMICAL FACTORS ON LUMINESCENCE PROPERTIES OF EUROPIUM (Ⅱ) ION

In this paper,the influence of crystal-field on the Luminescence properties of Eu~(2 ) in complex oxidesare studied theoretically by using purely electrostatic model,the dependence of the 4f~65d levels on Eu-Obond distance is given.Quantum chemistry calculation shows that the splitting extent of 4f~65d energy band incubic or in octahedral fields will be inversely proportional to R~5,where R is the distance of Eu~(2 ) to oxygenligand.The value of R affects slightly the location of the centre of 4f~65d energy band.According to the exper-imental spectrum data,we have discussed the influence of the host chemical composition,the replaced sites ofEu~(2 ) and degree of covalency of Eu-O bond on luminescence properties of Eu~(2 ).Some regularity offluorescence spectrum was observed.In alkali-alkaline earth-phosphates,the splitting extent of 4f~65d band (△E) becomes smaller as theEu-O bond distance (R) increases.In Na_(3-x)(PO_4)_(1-x)(SO_4)_x and Na_(2-x)CaSi_(1-x)P_xO_4 hosts,d-d emissionpeak of Eu~(2 ) will shift to shorter wavelength with the increase of x's value.The crystal structure data show that Eu~(2 ) in K_2Mg_2(SO_4)_3 is affected more strongly by crystal-fieldand covalancy than in KMgF_3,so K_2Mg_2(SO_4)_3:Eu~(2 ) emits blue light (E_(em)~m=400nm) and KMgF_3:Eu~(2 )produces ultraviolet fluorescence.     

稀土三基色荧光粉合成中的化学问题

稀土三基色荧光粉合成中的化学问题洪广言，李有谟，贾庆新，刘书珍，于德才，彭桂芳，董相廷（中国科学院长春应用化学研究所）稀士三基色荧光粉由红、绿、兰三种稀土离子激活的荧光粉组成。它是目前最重要的灯用稀土发光材料。自１９７４年荷兰菲利浦的Ｊ．Ｍ．Ｐ．Ｊ．...