MgAl2O4:Cr3+透明陶瓷的制备及其光谱特性研究

MgAl2O4 transparent ceramics can be widely applied to many fields such as laser, military and national defense because of its excellent optical properties. Its transmission band covers ultraviolet to infrared region, and has excellent and it has high physical and chemical stability and excellent radiation resistance. The transition metal Cr3+ doped crystals have strong broadband emission and long life. MgAl2O4:Cr3+ transparent ceramics will have the excellent performance of the two, which can be used as the gain medium of broadband optical amplifier in optical communication band. This project is based on the development of MgAl2O4:Cr3+ transparent ceramics with excellent performance, simple process as the goal, proposed by combining polymer precursor sol gel method and hydrothermal method. The prepared nano MgAl2O4:Cr3+ powder, spherical, uniform size distribution and high sintering activity, and fabrication of transparent MgAl2O4:Cr3+ ceramics by hot pressing sintering process; mechanism preparation and growth system of spherical MgAl2O4:Cr3+ nanoparticles, explore the densification mechanism of MgAl2O4:Cr3+ transparent ceramics, and combined with the first principle, to reveal the interaction mechanism of Cr3+ and MgAl2O4 luminescence center matrix and additives Y3+, which will promote the application of spinel transparent ceramics in the field of optical communication.

镁铝尖晶石透明陶瓷的透光波段覆盖紫外到红外区，光学性能优异，且兼具物化稳定性高、抗辐照性优异等特点，可广泛用于激光、军事国防等众多领域。过渡金属Cr3+掺杂的晶体具有较强的宽带发射且寿命长。铬掺杂的镁铝尖晶石透明陶瓷将兼具二者的优异性能，可作为光通信波段宽带光放大器的增益介质。本项目以开发性能优异、工艺简单的MgAl2O4:Cr3+透明陶瓷为目标，拟以聚合物前驱体溶胶凝胶法与水热法相结合的方法，制备出球形、粒度分布均匀、烧结活性高的纳米MgAl2O4:Cr3+粉体，再采用热压烧结工艺制备MgAl2O4:Cr3+透明陶瓷；系统研究球形MgAl2O4:Cr3+纳米粉体的制备工艺及生长机理，探索MgAl2O4:Cr3+透明陶瓷的致密化机理，并结合第一性原理，揭示发光中心Cr3+与基质MgAl2O4及烧结助剂Y3+间的相互作用机理，为MgAl2O4:Cr3+透明陶瓷在光通信领域的应用提供理论基础。

镁铝尖晶石透明陶瓷的透光波段覆盖紫外到红外区，光学性能优异，且兼具物化稳定性高、抗辐照性优异等特点，可广泛用于激光、军事国防等众多领域。过渡金属Cr3+掺杂的晶体具有较强的宽带发射且寿命长。铬掺杂的镁铝尖晶石透明陶瓷将兼具二者的优异性能，可作为光通信波段宽带光放大器的增益介质。本项目采用聚合物前驱体溶胶凝胶法与水热法相结合的方法，制备出近球形、粒度分布均匀的纳米MgAl2O4:Cr3+粉体，并研究了Y3+离子对Cr3+发光性能的影响。另外，采用热压烧结技术，制备出透光率高达80%的MgAl2O4:Cr3+透明陶瓷，并研究了热压烧结工艺，以及烧结助剂Y2O3、La2O3等对陶瓷结构、致密性以及发光特性的影响。研究表明，少量烧结助剂Y2O3、La2O3对MgAl2O4:Cr3+透明陶瓷的晶体结构没有明显影响，且可以促进晶粒生长，降低孔隙率，从而提高MgAl2O4:Cr3+透明陶瓷的透光率，其中Y2O3的作用更为显著。另外，Y2O3作为助剂时，还明显提高了Cr3+的红光发射的量子产率，当Y2O3用量为2.4wt%时，量子产率约为35.4%，荧光衰减时间约为7.683ms。这些研究结果为进一步改进MgAl2O4:Cr3+透明陶瓷的光谱特性提供了重要的参考价值，并对透明陶瓷在光通信领域的应用具有积极促进作用。