【摘要】 BaGdLaTi₃O₁₀是新的化合物,用X衍射分析得出与BaNd₂Ti₃O₁₀结构相同,是属正交晶系,点阵常数a=3.8658A,b=28.196A,c=7.3547A。为了寻找新的小型激光器的材料,对BaGd_1-xLa_1-xNd_2xTi₃O₁₀（BGLT₃）晶体进行了研究（其中0≤x≤1）。用提拉法生长出大小为φ15×25mm³的紫色晶体。观察了300—2500nm范围内室温下的吸收光谱,在350nm左右处出现很强的基质吸收。在400—1000nm范围内存在一些明显的吸收峰,吸收强度随Nd浓度增加而增加。BGLT₃系列晶体的吸收强度比YAG:Nd和GGG:Nd都强,而谱线的劈裂较之两者都少。测量了0.8—1.4μm之间的荧光谱,晶体对应⁴F_3/2—⁴I_13/2,⁴F_3/2—⁴I_11/2和⁴F_3/2—⁴I_9/2跃迁的荧光强度随Nd浓度的增加而减少;荧光寿命随Nd浓度增加而缩短,当x=0.01时,荧光寿命为160μs,当x=0.25时,荧光寿命为70μs。更多还原

【Abstract】 BaGdLaTi₃O₁₀ is a newly developed compound .Its structure has been determi-ned to be the same as that of BaNd₂Ti₃O₁₀ by X-ray powder diffraction, i.e. orthorhom-bic, a=3.8658A, b = 28.196A, and c=7.3547A. For the purpose of seeking new mini-laser materials, investigation on the crystals of BaGd_1-xLa_1-xNd_2xTi₃O₁₀system （0≤x≤1） have been made by the authors and the crystals of this system with x = 0, 0.01,0.05, 0.25, 0.5, 0.75 and 1.0 of dimensions up to φ15×25mm have been grown bythe Czochralski technique. High purity （>99.9%） reagents, BaCO₃, Gd₂O₃, Nd₂O₃,TiO₂ and La₂O₃, were used as the starting materials. These reagents were mixed in proper proportions and pressed into pellets. An iridium crucible was used which ser-ved as the susceptor for the R.F. coil at the same time. Crystals were pulled at a rateof 2 mm/h with a rotation rate of 20 rpm in a nitrogen atmosphere. The as-growncrystals were black in color but they changed into violet after annealing in air at1000℃ for 50 h. The absorption spectra of such crystals were determined by means of anoptical spectrometer in the wavelength range of 300--2500 nm at room temperature. Forall of the absorption spectra of these crystals, there are several absorption peaks dueto Nd³⁺ in the wavelength range of 400-1000 nm and a very strong absorption peak at350 nm. The positions of these peaks have no connection with the Nd³⁺ concentrationin crystals, but their intensities increase with the increase of the concentration ofNd³⁺. As compared with the absorption peaks of Nd: YAG or Nd: GGG, the intensities of theabsorption peaks of BaGd_1-xLa_1-xNd_2xTi₃O₁₀ crystals are higher but with less splittedspectral lines. The luminescent emission spectra of these crystals have also been studi-ed under the excitation by an Ar-laser of wavelength 478nm. The intensities of lumi-nescent emissions corresponding to the transitions ⁴F_3/2--⁴I_13/2, ⁴F_3/2--⁴I_11/2 and⁴F_3/2--⁴I_9/2 decreaae with the increase of the concentration of Nd³⁺, and the lumine-scence life times get shorter when the Nd³⁺ concentration is increased, e. g. 160μs forx = 0.01 and 70μs, for x= 0.25.更多还原