稀土氧化物在（Ba,Sr）TiO3基陶瓷材料中的应用

综述了稀土氧化物在各种作用的（Ba,Sr)TiO3基陶瓷中的掺杂改性和应用现状，详细讨论了稀土氧化物掺骠改性作用机理，分析了该领域应用研究的发展方向。为稀土氧化物掺杂改性（Ba,Sr)TiO3基陶瓷提供理论依据。     

稀土氧化物在陶瓷中的应用

针对我国稀土资源得天独厚的现状，从稀土元素的原子结构和化学特性出发，简略介绍了稀土的应用领域，较详细地阐述了稀土在陶瓷色釉料、功能陶瓷、各种氧化物陶瓷和非氧化物陶瓷中的应用。     

稀土氧化物在陶瓷工业中的应用

本文论述了稀土氧化物在陶瓷坯釉料，陶瓷颜料，陶瓷金水，工业陶瓷等方面的应用研究，初步探讨了稀土氧化物的作用机理，表明了稀土氧化物在陶瓷工业中有着广泛的作用并有着广阔的应用前景。     

稀土氧化物对Na_(0.5)Bi_(0.5)TiO_3基无铅压电陶瓷结构和性能的影响

综述了稀土氧化物在Na0.5Bi0.5TiO3(BNT)基无铅压电陶瓷中的应用现状和发展前景,并阐述了稀土氧化物在BNT基无铅压电陶瓷中的作用机理。     

稀土氧化物在陶瓷涂层中的应用

综述了稀土氧化物在陶瓷涂层中的应用状况,论述了稀土氧化物对陶瓷涂层的力学性能、抗热震性能、耐磨性和耐蚀性的影响,认为稀土氧化物对陶瓷涂层的改性作用主要表现在细化晶粒、净化组织、产生固溶强化和弥散强化等方面。     

倍半氧化物激光陶瓷的研究进展

倍半氧化物透明陶瓷具有声子能量低、热膨胀系数低、损伤阈值高、热导率高等优势,在固体激光领域有着极大的应用前景。提出了研制高质量倍半氧化物透明陶瓷亟需解决的瓶颈问题,阐述了在倍半氧化物陶瓷制备过程中提高光学质量、减少晶格缺陷的关键措施,总结了稀土离子掺杂倍半氧化物陶瓷在1～3μm波段固体激光器应用中的代表性成果,并对倍半氧化物激光陶瓷的未来发展进行了展望。     

复合稀土氧化物对氧化铝陶瓷耐磨性能的影响研究

讨论了不同类型和不同量的六种稀土氧化物La2O3、ceO2、Y2O3、Sm2O3、Nd2O3、Dy2O3对氧化铝陶瓷进行掺杂的试验过程,研究表明：某两种或两种以上稀土氧化物一起添加到氧化铝陶瓷中,比单一稀土氧化物添加到氧化铝陶瓷中对提高陶瓷耐磨损性能的效果要好。     

粒子弥散强化氮化硅基陶瓷

运用晶界工程理论，选择能形成高耐炎度晶界相的Ｙ２Ｏ３和Ｌａ２Ｏ３双稀土氧化物为Ｓｉ３Ｎ４陶瓷烧结助剂，材料具有优异的高温强度。第二相碳化硅粒子的引入有效地改善了氮化陶瓷的显微结构和力学性能。以无压烧结工艺制备的高性能α／β－Ｓｉａｌｏｎ复相陶瘊等在实际应用中获得良好效果。     

几种新型铒变色颜料的研究

用饵氧化物并添加其它稀土氧化物及过渡金属氧化物合成出了新型陶瓷光致变色颜料。在进行理论分析的基础上，通过试验得出较佳的合成温度和配比。     

稀土氧化物在Al2O3透明陶瓷晶界浓度分布的非平衡态热力学分析

采用高纯Ａｌ２Ｏ３超细粉末,烧制成掺杂稀土氧化物的Ａｌ２Ｏ３透明陶瓷。以ＥＰＭＡ法观测透明陶瓷晶界处的化学组成及稀土氧化物的定态浓度分布,用非平衡态热力不理论分析晶界偏析行为,研究发现,添加物在Ａｌ２Ｏ３透明陶瓷晶界的浓度分布为非平衡态和学组成分布,ＭｇＯ,Ｌａ２Ｏ３,Ｙ２Ｏ３富集于晶界,符合定态耦合模型。     

Effects of rare-earth doping on the ionic conduction of CeO2 in solid oxide fuel cells

Rare-earth-doped CeO₂ have been found to enhance the ionic conductivity of ceria-based electrolytes in solid oxide fuel cells (SOFCs) because trivalent rare-earth cations can spontaneously induce oxygen vacancies. Experimentally, it has been shown that the rare-earth elements La, Nd, Sm, Gd, Tb, Dy, and Er are likely candidates for electrolyte doping. However, the performances differ for the trivalent cations, suggesting that rare-earth doping plays multiple roles instead of only increasing the oxygen vacancies. First-principles calculations are performed on a series of rare-earth-doped CeO₂ systems to study the doping effects on the ionic conductivity. It is found that the migration barriers of the oxygen ions are significantly different for the different dopants and depend on the dopant's radius. Gd-, Dy-, Er-, and Tb-doping results in small migration barriers and enhances the ionic conductivity. We also calculate the formation energies (E_vac) of the intrinsic oxygen vacancies due to thermal excitation. It is found that the Sm- and Gd-doped ceria systems have the smallest E_vac values. The electronic structures indicate that the band gaps are not sensitive to the dopant elements but are very sensitive to the fluctuations in the oxygen content.     

(Na1/2Bi1/2)TiO3系无铅压电陶瓷材料研究进展

概述了近年来国内外(Na1/2Bi1/2)TiO3(BNT)基无铅压电陶瓷的研究近况。主要介绍BNT陶瓷及BNT基陶瓷的研究工作。通过非化学计量掺杂及A位空位的存在，使BNT基陶瓷的电性能得到了较大的提高。     

Bi掺杂Ba0.6Sr0.4TiO3陶瓷的研究

本文采用传统的陶瓷工艺合成了Ba0.6Sr0.4TiO3陶瓷,研究了Bi掺杂对材料参数ε、tanδ和E的影响,并探讨了相关的掺杂改性机理。结果表明：适量的Bi能够改善陶瓷的介电性能,同时细化陶瓷的晶粒尺寸。     

Dielectric properties and diffuse phase transition behavior of CuO-doped lead-free Ba(ZrxTi1−x)O3 ceramics

CuO-doped lead-free Ba(Zr_0.2Ti_0.8)O₃ (BZT20) ceramics were prepared through a solid state processing technique, and the effects of CuO on microstructure, dielectric properties and diffuse phase transition behavior were investigated. The average grain sizes were increased by CuO doping. The temperature and frequency dependences of the dielectric constant revealed that CuO-doped BZT20 ceramics exhibited broad diffuse phase transition behavior. The dielectric constant increased with increasing CuO concentration. The value of T_m and degree of diffusion (γ) changed regularly in the studied compositional ranges. The BZT20 samples with 1.0 mol% CuO doping, sintered at 1310 °C, showed excellent dielectric property and lower diffusivity with ε_m=21,371 and γ=1.87. These results can be explained by the disordered distribution of Cu ions in the B sites and the weakened bonding force with oxygen ions in Cu substituted BZT20 structure.     

Thermal Conductivity of β-Si3N4: III, Effect of Rare-Earth (RE = La, Nd, Gd, Y, Yb, and Sc) Oxide Additives

β-Si₃N₄ ceramics sintered with a series of rare-earth (RE = La, Nd, Gd, Y, Yb and Sc) oxide additives were fabricated by hot pressing and subsequent annealing. Their microstructures, lattice oxygen contents, and thermal conductivities were evaluated. Mean grain size increased, while lattice oxygen content decreased, and hence, thermal conductivity increased with decreasing ionic radius of the rare-earth element. In all cases, a marked change was observed in the order of ionic radius from La to Nd to Gd, and a little change was observed below them. Rare-earth oxide additives significantly influenced the thermal conductivity of β-Si₃N₄, unlike in the case of AlN.     

稀土在高铝瓷中的应用研究

研究了不同稀土对高铝瓷烧结性能及瓷质性能的影响,结果表明Ｙ２Ｏ３及富钇混合稀土氧化物能显著降低高铝瓷的烧结温度,使瓷质增韧,提高耐磨性,而且其效果与制备稀土氧化物的母盐有关,合适的稀土氧化物加人量为０．３％～０．７％,过少和过多的加入对瓷质性能无益。     

Effect of Rare-Earth Ions on Electrical Conductivity of BaTiO3 Ceramics

Lattice constants, grain size, electrical conductivity, and luminescence were measured for sintered BaTiO₃ ceramics doped with 0 to 1.2 at.% rare-earth ions. BaTiO₃ doped with low levels of rare-earth ions contains grains 10 μm in size and has lattice constants nearly equal to those of undoped ceramics. In this case, rare-earth ions occupy Ba²⁺ sites and yield donors. When grain growth is inhibited by high doping levels or by insufficient sintering, the lattice constants change, the rare-earth ions occupy both Ba²⁺ and Ti⁴⁺ sites, and, consequently, BaTiO₃ becomes insulative because of charge compensation.     

Reversible and color controllable emissions in Er3+/Pr3+-codoped K0.5Na0.5NbO3 ceramics with splendid photochromic properties for anti-counterfeiting applications

It is highly significant to develop multi-mode optical anti-counterfeiting materials to efficiently fight against counterfeit products. In this study, we chose ferroelectric K_0.5Na_0.5NbO₃ (KNN) with excellent photochromism properties as the host and rare-earth Er³⁺ and Pr³⁺ ions as dopants to prepare the Er³⁺/Pr³⁺-codoped KNN ceramics. The color-tunable emissions can be obtained from red-orange-yellow to green by controlling the excitation wavelength. Upon 980 nm excitation, the synthesized ceramics does not only have superior upconversion (UC) emission behaviors but also have good luminescence modulation properties based on the photochromism properties. It is found that the KNN:0.003Er³⁺/0.003Pr³⁺ sample with the optimal UC emission features shows a highest ΔR_t value of 74.52% when irradiated by 390 nm light for 5 min, whereas the KNN:0.005Er³⁺/0.003Pr³⁺ ceramics also exhibit a high ΔR_t value of 66.81% under 395 nm light irradiation. According to the XPS and EPR results, one knows that the mechanism of luminescence modulation is closely related to defects and traps caused by the oxygen vacancies. Furthermore, the optical information writing and erasing test is conducted, exhibiting a good reproducibility and fatigue resistance. These results reveal that the designed ceramics are appropriate for the anti-counterfeiting applications.     

固体氧化物燃料电池双钙钛矿阴极材料PrBaCo2O5+δ的掺杂改性

固体氧化物燃料电池(SOFC)是一种清洁、高效的能量转换装置,其性能受制于阴极的氧还原反应,钴基双钙钛矿氧化物PrBaCo₂O_5+δ具有较高的氧表面交换系数和体扩散系数,是近年来备受重视的阴极催化材料。然而,PrBaCo₂O_5+δ在SOFC中的应用受到热膨胀匹配性差等的制约,为此,大量的工作研究了PrBaCo₂O_5+δ的掺杂改性。本文综述了各种掺杂研究,按照掺杂位置分别总结了Pr位、Ba位、Co位和O位的掺杂元素和掺杂量,结合钙钛矿的容忍因子,讨论了掺杂对PrBaCo₂O_5+δ性能的影响,包括晶体结构、氧的非化学计量δ、电导率、热膨胀系数、氧传输性能和电化学性能等。