CAJ | 학술논문

采用CS2硫化法制备γ-La2S3时,通过掺入Eu离子,使γ-La2S3的生成温度降低500℃以上,在700℃就能得到稳定的γ-La2S3。掺入的Eu离子,充当γ-La2S3成核的晶种,从而降低γ-La2S3的生成温度。一部分Eu2＋通过不等价取代La3＋,同时在晶格中形成S空位以保持电中性;另一部分Eu2＋则填入γ-La2S3的S4四面体空洞,从而稳定了γ-La2S3的晶体结构,使其能够在1100℃下仍能保持稳定。在硫化反应过程中,Eu的掺杂使相变过程发生变化,La2S3不再经过β→γ相变,而直接由介稳相LaS2转变为γ-La2S3。光谱分析表明,在244nm紫外光激发下,掺Eu的γ-La2S3在280、390以及570nm处有3个发射带,且390nm发射峰非常强,可能源于缺陷发光,而Eu2＋的发光很弱或不发光。
채용CS2류화법제비γ-La2S3시,통과참입Eu리자,사γ-La2S3적생성온도강저500℃이상,재700℃취능득도은정적γ-La2S3。참입적Eu리자,충당γ-La2S3성핵적정충,종이강저γ-La2S3적생성온도。일부분Eu2＋통과불등개취대La3＋,동시재정격중형성S공위이보지전중성;령일부분Eu2＋칙전입γ-La2S3적S4사면체공동,종이은정료γ-La2S3적정체결구,사기능구재1100℃하잉능보지은정。재류화반응과정중,Eu적참잡사상변과정발생변화,La2S3불재경과β→γ상변,이직접유개은상LaS2전변위γ-La2S3。광보분석표명,재244nm자외광격발하,참Eu적γ-La2S3재280、390이급570nm처유3개발사대,차390nm발사봉비상강,가능원우결함발광,이Eu2＋적발광흔약혹불발광。
The CS2 sulfurization method was adopted to synthesize Eu doped γ-La2 S3. The addition of Eu reduces the synthesis temperature with about 500℃ and stabile γ-La2S3 can be obtained at 700℃. The added Eu2+ acts as the seeds to facilitate the formation of the γ-La2S3 phase at quite low temperature. Parts of added divalent Eu2+ ions replace trivalent rare earth La3+ ions and S vacancies are left as charge compensation. In the mean- time, the rest Eu2+ ions can be inserted into the empty tetrahedral S4 cavities to fix the structure of γ-La2 S3 and stabilize the γ-La2S3 phase at temperature of 1100℃. During the reaction process, the doped Eu ion directly make metastable LaS2 phase transform to γ-La2 S3 at rather low temperature without the β→γ phase transforma- tion. Excited by 244nm, γ-La2S3 : Eu exhibits three emission band centered at 280, 390 and 570nm, respective- ly. The strong 390nm peak was probably originated from the defect emission and the Eu2+ emission was very weak or no luminescence at all.