溴氧化镧:铽荧光粉的水解及其防御机理的研究（Ⅰ）

溴氧化镧:铽荧光粉的水解及其防御机理的研究（Ⅰ） THE STUDY OF MECHANISM OF HYDROLYSIS OF LANTHANUM OXYBROMIDE: TERBIUM PHOSPHOR AND ITS PROTECTION（Ⅰ） 孙聚堂 Sun Jutang Jiang Changwu He Xiqing Du Xiuzhen first-author 蒋昌武 何喜庆 杜秀珍 <正> 引言溴氧化镧:铽荧光粉是一种高效率的X线发光材料,Blasse[1]等首先报导了这类发光材料。可能由于制成品的化学组成偏离或结晶不好,以致当时所测得的发光效率极低。1971年,据美国通用电气公司Rabatin报导,他们制得了高效率X线发光荧光粉LaOBr:Tb（Ce）和GdOBr:Tb（Ce）[2],并制成了X线像变换器[3]。这种发光材料的发光效率很高,引起了人们的注意。随后Rabatin发表了一系列有关的研究报告[4-8]。北京大学等单位也于1977年先后试制了上述发光材料[9]。溴氧化镧:铽荧光粉的发光效率约为20%[10],大约是通常所用钨酸钙荧光粉的4～6倍,对X线的吸收效率比钨酸钙增加50%以上,同时,兰色发光的辐射量增大3～4倍[12]。目前, The mechanism of hydrolsis of lanthanum oxybromide: terbium phosphor is studied through electric conductance determination. The hydrolytic reaction of lanthanum oxybromide in water is an autocatalytic reaction. The endpreducts of hydrolysis are precipitate of La（OH） 3 and solution of LaBr 3 . During hydrolysis of lanthanum oxybromide, an active intermediate La（OH） 2 Br, which is called a hydrolyst, is formed. The influence on the hydrolytic reaction is also discussed. The ions, such as H + 、OH - or La 3+ , are added in to the hydrolytic system of lanthanum oxybromide, or small quantity of unsolvable substances, such as aluminium silicate、 zinc silicate、aluminium phosphate or aluminium hydroxide etc, are deposited on the surface of crystal grains of lanthanum oxybromide phosphor, thus can ideally protect lanthanum oxybromide phosphor from hydrolysis. 1981-01-01 2021-04-01 1