通过溶胶-凝胶法制备出一系列Dy3+掺杂的Y2MgTiO6(YMT∶Dy3+)荧光粉, 并利用X射线衍射仪、扫描电子显微镜、荧光光谱仪对荧光粉的晶体结构、微观形貌及发光性质进行研究和分析。研究结果显示, YMT∶Dy3+荧光粉为双钙钛矿结构, Dy3+掺杂不改变样品的晶体结构。在近紫外光(352 nm)的激发下, 样品的发射光谱显示出典型的Dy3+特征发射峰, 分别是485 nm处的蓝光、578 nm处的黄光, 以及650~700 nm的红光。当Dy3+摩尔浓度x=0.03时, 荧光粉出现浓度猝灭效应, 其浓度猝灭机制为电偶极子-电偶极子相互作用(d-d)。YMT∶Dy3+荧光粉的CIE色坐标明显受到Dy3+的浓度影响, 其中YMT∶0.02Dy3+荧光粉的CIE色坐标为(0.406, 0.407), 位于暖白光区, 可作为一种暖白光荧光粉应用于近紫外激发白光发光二极管(w-LEDs)。

双层钙钛矿结构氧化物具有优异的离子电子电导率，作为固体氧化物燃料电池（SOFC）阴极材料被广泛研究。以PrBaCo2O5+δ作为母体材料，采用Ca离子在Pr位和Ba位进行掺杂，采用溶胶凝胶法制备出了Pr0.9Ca0.1Ba1-xCaxCo2O5+δ(0≤x≤0.3，PCBC)阴极材料。电导率测试结果表明：Ca离子共掺杂能够有效改善材料的电导率。电化学性能测试结果表明：x=0.2的阴极具有最佳的氧催化活性，700 ℃时极化阻抗仅为0.069 ?偸cm2。在理论研究中，通过GGA-PBE泛函分别计算了PrBaCo2O5+δ、Pr0.75Ca0.25BaCo2O5+δ与Pr0.75Ca0.25Ba0.75Ca0.25Co2O5+δ的氧空位形成能、态密度及O s和O p的能带中心。研究发现，Pr位掺Ca能减小氧空位形成能，Ba位掺杂Ca反而会增大氧空位形成能。O p带中心的计算结果表明：Ba位掺Ca的策略有效增加了材料的氧还原活性。双钙钛矿A位钙离子的共掺杂策略能够有效改善样品的热膨胀、高温电导率和电化学性能，提高材料的长期稳定性。

双钙钛矿结构化合物具有化学稳定性高、声子能量低、易于稀土离子掺杂和多种可调变的晶体学格位等优点，是一种优良的上转换发光基质材料。本文采用高温固相法在600 ℃下合成了双钙钛矿结构Rb3GaF6∶Er3+,Yb3+上转换发光材料，并采用X射线粉末衍射仪(XRD)、场发射扫描电镜(SEM)和荧光光谱仪对其成分、结构和发光特性进行系统表征。在980 nm激发下，制备的样品在521和548/561 nm处产生的绿光发射分别归因于Er3+的2H11/2-4I15/2、4S3/2-4I15/2能级上的电子跃迁，同时在656 nm处产生的红光发射对应于Er3+的4F9/2-4I15/2能级上的电子跃迁。此外，本文探究了Rb3GaF6∶Er3+,Yb3+的上转换发光机理。

Sr3Sn2O7:Sm3+是一种被广泛研究的应力法光材料, 但关于 Sm3+掺杂量的研究仍然存在缺失。本工作采用高温固相法制备 Sr3-xSn2O7:xSm3+。在 Sr3Sn2O7中掺入少量 Sm3+后, 样品仍然保持着非中心对称的双钙钛矿结构。样品在受到紫外灯激励或应力施加之后, 能展现出稳定的光致发光、长余辉和应力发光性能, 且这三者的光谱显示出一致性。应力发光来源于 Sm3+的 4G5/2激发态向 6HJ (J=5/2, 7/2, 9/2)基态的电子跃迁。通过调控 x值对其发光性能进行优化, 在 x=0.020时性能昀好。Sm3+掺杂量的变化对应力发光性能的影响, 既对现有的相关工作进行了补充, 同时也能为未来的相关研究起到参考或指导的作用。

通过改进的自蔓延燃烧法合成制备高熵双钙钛矿SmBa(Mn0.2Fe0.2Co0.2Ni0.2Cu0.2)2O5+δ (HE-SBC)阴极材料，并复合10%(摩尔分数)Gd2O3掺杂CeO2(GDC)以优化性能。结果表明：通过B位高熵的方法可以显著减小Co离子由价态变化而引起的热膨胀，从而降低SmBaCo2O5+δ 的热膨胀系数。在800 ℃，以氧化钇稳定氧化锆(YSZ)为电解质的HE-SBC对称电池的极化阻抗(Rp)为1.04 Ω·cm2，阳极支撑单电池的最高功率密度和Rp分别为683.53 mW/cm2和0.46 Ω·cm2。进一步通过复合GDC (HE-SBC与GDC的质量比7:3)以增加三相界面提高HE-SBC的催化活性，在800 ℃ HE-SBC-GDC复合阴极对称电池的极化阻抗仅为0.09 Ω·cm2，且阳极支撑单电池的最高功率密度和Rp分别为838.66 mW/cm2和0.12 Ω·cm2。

Cr3+激活荧光粉因其具有远红光和近红外光发射的特性而受到广泛关注。本研究合成了一系列(La,Gd, Y)2MgTiO6∶Cr3+荧光粉, 在345 nm紫外光激发下, 其发射波段为700~900 nm。采用离子取代策略对其光谱进行了调谐, 通过Gd或Y取代La位点, 发射主峰从766 nm分别蓝移至737 nm和757 nm; 150 ℃下的热稳定性从41.7%分别提升至69.1%和67%。系统研究了荧光粉的晶体结构、微观形貌、荧光寿命、热稳定性能和带隙变化等。Gd和Y离子取代会导致晶格收缩, 引起电子云重排效应变化, 最终导致发射光谱蓝移。改性后荧光粉的发射光谱与光敏色素FR(PFR)的吸收(730 nm)具有更好的匹配性, 表明其在植物生长照明中的应用前景, 这也证明通过阳离子取代策略调控Cr3+的发光性能可为未来植物生长灯用荧光粉的研发提供思路。

In the search for new materials with applicable magnetic properties in spintronic devices, the aim of this work is to report the synthesis of the lanthanide ferrocobaltite La₂CoFeO₆ using the modified Pechini route; the experimental study of structural, morphological and magnetic properties, and the analysis of the electronic structure and bands are obtained in the framework of the Density Functional Theory. Rietveld refinement of experimental X-ray diffraction patterns revealed the crystallization of this oxide material in a perovskite-like monoclinic structure, space group P2₁/n (# 14). Scanning electron microscopy and atomic force microscopy images revealed that the surface morphology is essentially polycrystalline, with mean grain sizes between 177 and 188 nm. The dispersive X-ray spectroscopy suggests that the material obtained contains La, Fe, Co and O in the stoichiometric proportions expected by up to 98%. The magnetic susceptibility curves as a function of temperature indicated that the material is ordered ferromagnetically, showing strong irreversibility effects due to the disorder of the Fe and Co cations in the three crystallographic directions of the structure and to the strong distortions in the FeO₆ and CoO₆ octahedra. Magnetic hysteresis curves confirmed the ferromagnetic character of the material for all temperatures evaluated, up to room temperature. I–V response curves revealed a semiconductor-like behavior with a figure of merit exponent 1.53 of the varistor type. The ferromagnetic semiconductor behavior suggests the potential applicability of the material in spintronic technological devices.In the search for new materials with applicable magnetic properties in spintronic devices, the aim of this work is to report the synthesis of the lanthanide ferrocobaltite La₂CoFeO₆ using the modified Pechini route; the experimental study of structural, morphological and magnetic properties, and the analysis of the electronic structure and bands are obtained in the framework of the Density Functional Theory. Rietveld refinement of experimental X-ray diffraction patterns revealed the crystallization of this oxide material in a perovskite-like monoclinic structure, space group P2₁/n (# 14). Scanning electron microscopy and atomic force microscopy images revealed that the surface morphology is essentially polycrystalline, with mean grain sizes between 177 and 188 nm. The dispersive X-ray spectroscopy suggests that the material obtained contains La, Fe, Co and O in the stoichiometric proportions expected by up to 98%. The magnetic susceptibility curves as a function of temperature indicated that the material is ordered ferromagnetically, showing strong irreversibility effects due to the disorder of the Fe and Co cations in the three crystallographic directions of the structure and to the strong distortions in the FeO₆ and CoO₆ octahedra. Magnetic hysteresis curves confirmed the ferromagnetic character of the material for all temperatures evaluated, up to room temperature. I–V response curves revealed a semiconductor-like behavior with a figure of merit exponent 1.53 of the varistor type. The ferromagnetic semiconductor behavior suggests the potential applicability of the material in spintronic technological devices.