采用一种新的定向方法,快速定出了Ag Ga0.7In0.3Se2晶体c轴方向,制备得到[001]、[100]方向的块状样品;采用德国Bhr公司的Win TA 100热膨胀仪对其进行测试,分别获得了晶体沿c轴、a轴方向的热膨胀系数,分析了它们随温度变化的规律以及晶体出现反常热膨胀的机制;计算出晶体的体热膨胀系数和各向异性因子,分析讨论了晶体非轴向热膨胀系数在不同温度下随cos2φ的变化规律。
发光晶体化合物在诸如照明与显示、光信息安全、生物医疗等领域已有广泛应用。文章通过高温固相法成功合成了基于SrSeO3基质Bi3+、Eu3+和Ce3+离子掺杂的发光晶体化合物。通过X射线衍射分析发现样品均属于具有正交晶系结构的SrSeO3晶体,空间群为Pnma (62),并且Bi3+、Eu3+和Ce3+倾向于取代[SrO9]中的Sr2+格位。常温光致光谱的测试表明,紫外光可有效激发Bi3+、Ce3+和Eu3+掺杂SrSeO3样品,分别发射出可归属于3P1 → 1S0 (Bi3+)、5d → 4F (Ce3+)和5D0 → 7Fj (Eu3+)的特征发射峰。此外,基于荧光衰减曲线测试的结果,发现SrSeO3基质与掺杂离子间存在能量传递。据此,构建了机理模型对样品可能存在的发光来源进行了分析。Luminescent crystal compounds have been widely applied in various fields, including but not limited to lighting and display, optical information security, and biomedical purposes. In this work, a series of luminescent crystal compounds that used the SrSeO3 as the host matrix for trivalent Bi3+, Eu3+, and Ce3+ ions doping were successfully synthesized using the high-temperature solid-state reaction method. The X-ray diffraction results indicated that the as-obtained samples belong to an orthorhombic-phased SrSeO3 crystal with a space group of Pnma (62), and the Bi3+, Eu3+, and Ce3+ dopants show a preferential substitution for Sr2+ sites in the [SrO9] polyhedra. Room temperature photoluminescent spectra revealed that the Bi3+, Ce3+, and Eu3+ doped SrSeO3 samples can be effectively excited with ultraviolet light, showing the emission spectra that can be attributed respectively to the characteristic transitions of 3P1 → 1S0 for Bi3+, 5d → 4F for Ce3+, and 5D0 → 7Fj for Eu3+. Besides, based on the measured fluorescent decay curves and their fitting results, an energy transfer from the SrSeO3 host matrix to the Bi3+, Eu3+, and Ce3+ dopants was revealed. Accordingly, a feasible mechanism that can be used to explain the possible luminescent origi
采用改进的布里奇曼法生长出Cd Si P_2单晶体,运用X射线能谱仪、傅里叶变换红外分光光度计以及红外显微镜等对在不同气氛中退火前后的Cd Si P_2晶体进行了组分元素、红外吸收系数以及红外透过均匀性测试,根据红外显微镜Mapping图像的标准差值评判了晶体的红外透过均匀性。研究结果表明,经真空、Cd Si P_2粉末包裹、P/Cd（原子比为2：1）、Cd气氛等退火后,晶体组分元素的化学计量比、红外吸收系数和红外光学均匀性都得到了不同程度的改善,其中在1.29～2.00μm,经Cd Si P_2粉末包裹退火后的晶体吸收系数改善显著,在1.92～1.98μm波段的红外透过均匀性提高了14.06%;而在Cd气氛下退火后晶体的吸收系数在2.00～6.50μm波段降低最为明显,在2.70～2.78μm波段红外透过均匀性提高了17.43%。分析讨论了在上述波段中引起晶体红外吸收和红外透过不均匀性的主要因素,研究出较为有效的Cd Si P_2晶体退火工艺。
