Application of rare earth in functional ceramics

Application of rare earth in functional ceramics
It mainly includes the following aspects: superconducting ceramics, piezoelectric ceramics, conductive ceramics, dielectric ceramics and sensitive ceramics.
With the development of material science, functional composite ceramics have attracted much attention in recent years, and rare earth doping has also made great progress in the development and research of functional composite ceramics. Chen Ang, et al. of Zhejiang University, used the conventional preparation method of functional ceramics to composite YBa2Cu3O7-x with ferroelectric ceramic BaTiO3 to obtain YBa2Cu3O7-x-BaTiO3 series composite functional ceramics with coexistence of ferroelectricity and superconductivity. Its conductivity characteristics conform to the three-dimensional conductive behavior, and it is superconducting when the content of YBa2Cu3O7-x is high. Zhou Dongxiang and others from Huazhong University of Science and Technology pointed out that LaCoO3 SrCoO3 system and LaCrO3 SrCrO3 system composite functional ceramics can be used as electrode materials and gas sensing materials for MHD motors; In the NTC thermosensitive composite NiMn2O4-LaCrO3 ceramics, the new compound LaMnO3 conductive phase determines the main properties of the ceramics. Zou Qin of Xi'an Jiaotong University and others, by doping (Sr, Ca) TiO3 with rare earth ions Y3+and La3+, have eliminated the original process of coating with alkali metal ions (Nb5+, Ta5+) and conducting thermal diffusion. Moreover, the ceramics produced have high density, good process performance and low resistivity（ ρ 10-2 Ω/cm), high nonlinearity (nonlinear coefficient α >10).
Intelligent ceramics are a kind of functional ceramics with the characteristics of self diagnosis, self adjustment, self recovery and self conversion. As mentioned above, the lead lanthanum zirconate titanate (PLZT) ceramic obtained by adding rare earth lanthanum into the lead zirconate titanate (PZT) ceramic is not only an excellent electro-optical ceramic, but also a smart ceramic because of its shape memory function, which reflects the self tuning mechanism of shape self recovery. The concept of intelligent ceramic materials advocates a new concept of developing and designing ceramic materials, which is very beneficial to broaden the application of rare earth in modern functional ceramics. Recent studies also show that rare earths also play a unique role in new ceramic materials such as bioceramics and antibacterial ceramics. As rare earth elements can synergize with transition elements such as silver, zinc and copper, the developed rare earth composite phosphate antibacterial can produce a large number of hydroxyl radicals on the surface of ceramics, thus enhancing the antibacterial performance of ceramics.
We should give full play to the advantages of rare earth resources in China, further strengthen the research on the influence of rare earth doping on the performance of functional ceramics and the development of new functional ceramics, and effectively enhance the application value of rare earth in high-tech materials.
Rare earth ceramic pigment mainly refers to a combination of five colors to color zircon based rare earth ceramic pigment. It can be used as decorative material of building ceramics such as colored glazed tiles, exterior wall tiles and floor tiles, especially for the decoration of sanitary ware ceramics, and also as the color base of overglaze, underglaze and underglaze colors of porcelain. The composite colored zircon based rare earth ceramic pigment is prepared by solid state reaction at 900~1150 ℃ with zirconia and silica as the matrix materials, transition elements and rare earth elements as the composite colorants, and a small amount of mineralizer. The main technical indicators are as follows: the color phases are red, yellow, blue, green and gray, the stability is less than or equal to 1280 ℃, and the maximum temperature can reach 1300 ℃), the applicable atmosphere is oxidation flame, and the particle diameter is less than 15 μ Not less than 92% and more than 30% of m μ M is zero.