Research progress of rare earth doped thermal barrier coatings

Effects of rare-earth dopants on phase structure and electrical properties of lead-free bismuth sodium titanate-based ceramics

CexZr1-xO2 (CZ) plays an important role in many environment catalytic fields such as automobile three-way catalysts (TWCs), but improving their thermal stability is still a great challenge. In this work, a strategy was proposed to enhance the thermal stability of CZ by combining experiment with ab-initio molecular dynamics (AIMD) method. It is found that the thermal stability of Ce0.35Zr0.60M0.05O2 (M represent La, Y, and Nd elements) could be adjusted by doping the suitable rare earth (RE) elements in the surface of CZ. With this strategy, the thermal stability of Ce0.35Zr0.60M0.05O2 (CZ-Y) with surface doping of Y is highest among these Ce0.35Zr0.60M0.05O2 samples. In comparison with the CZ sample without doping (specific surface area SSA=20.16 m2⋅g-1), CZ-Y exhibit superior thermal stability (SSA=26.83 m2⋅g-1) after thermal treatment (1100 °C/10 h). To give a deep insight into the RE doping effects, the thermal displacement rate (TDR) of Ce0.35Zr0.60M0.05O2 are further calculated by AIMD. It is found that CZ-Y has the lowest TDR values, which is beneficial for suppressing the thermal displacement of atoms and improving the thermal stability of CZ. This study provides a deep insight into the origin of rare earth (RE) doping effect on CexZr1-xO2 (CZ), which is of fundamental interest for the development of high performance CZ in practical applications.

Effect of doping rare earth oxides (RE= Sc, Y, Gd, Eu) on structural, thermal and mechanical properties of La2(Zr0.7Ce0.3)2O7 ceramics

Bi2Sr2CaCu2O8+∂ samples have been successfully synthesized by doping rare earth (RE) variations using wet-mixing method. Samples calcined at 600°C for 3 hours and sintered at 850°C for 10 hours. The purpose of research is to determine the effect of the RE dopant on the microscopic structure of BSCRECO superconductors. Therefore, the research was conducted characterization by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). Measurements with XRD could be carried out and crystal system of Bi2Sr2CaCu2O8+∂ with rare earth (RE) dopants could be determined clearly. Generally, crystallization has occurred very well demonstrated by the diffraction peaks are sharp, which is dominated by the emergence of Bi-2212 phase. Search match results of XRD spectrum showed Bi2Sr2CuOx (2201) and Ca2CuO3 (21) as an impurity phase with small intensity. Also, that is showing volume fraction from 85 to 92% and orthorombic value for all samples from 5 to 7%. The effect of RE dopants resulted a shift angle 2θ and changes in the volume of the unit cells of each sample. The value of the unit cell volume of the largest to smallest is BS(CN)CO, BS(CNG)CO, BS(CNEG)CO, BS(CNE)CO, BS(CG)CO, BS(CEG)CO and BS(CE)CO. Measurement with FTIR showed the bending vibration absorption by CO32- in the wavelength range between 1500 and 1520 cm-1, vibration of M-O between 420 and 650 cm-1, the complex formation of BSCCO in the wavelength range between 1690 and 1700 cm-1. Measurement with SEM showed rod shape with particle size in hundreds nanometer.

Advanced thermal barrier coatings (TBCs) have been developed by incorporating multicomponent rare earth oxide dopants into zirconia-based thermal barrier coatings to promote the creation of the thermodynamically stable, immobile oxide defect clusters and/or nanophases within the coating systems. In this paper, the defect clusters, induced by Nd, Gd, and Yb rare earth dopants in the zirconia-yttria thermal barrier coatings, were characterized by high-resolution transmission electron microscopy (TEM). The TEM lattice imaging, selected area diffraction (SAD), and electron energy-loss spectroscopy (EELS) analyses demonstrated that the extensive nanoscale rare earth dopant segregation exists in the plasma-sprayed and electron-physical-vapor-deposited (EB PVD) thermal barrier coatings. The nanoscale concentration heterogeneity and the resulting large lattice distortion promoted the formation of parallel and rotational defective lattice clusters in the coating systems. The presence of the 5-to 100-nm-sized defect clusters and nanophases is believed to be responsible for the significant reduction of thermal conductivity, improved sintering resistance, and long-term high temperature stability of the advanced thermal barrier coating systems.

Effect of rare earth doping on the hydrogen storage performance of Ti1.02Cr1.1Mn0.3Fe0.6 alloy for hybrid hydrogen storage application

The effect of rare earth dopants on grain boundary cohesion in alumina

Effect of rare earth doping on electronic and gas-sensing properties of SnO2 nanostructures

Effects of rare-earth doping and reduction processes in LiCaPO4 compound: A computer simulation study

Planar silica waveguide devices offer the possibility for cheap, mass produceable components for optical networks and sensors. So far, such devices have been passive in nature. It is now possible to greatly increase the device functionality by making use of the property of photosensitivity and the effect of rare earth doping in such devices. This paper discusses the results of photosensitivity, and rare-earth doping in silica waveguide devices fabricated using Flame Hydrolysis Deposition. As regards photosensitivity, the paper will consider the basic material effects, grating writing and direct writing of waveguides. Rare earth doping is also possible in such waveguides, and the results of such work are described. Rare earth doping involves solution doping of a porous soot, followed by consolidation to incorporate the rare earth. Issues such as clustering of the rare earth and ion-ion interaction leading to gain quenching are discussed and techniques to reduce deleterious presented. Possibilities for combining photosensitivity and rare earth doping are described which offer the potential for waveguide devices containing passive, photosensitive and active sections on different parts of the same wafer.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Rare-earth doped Ni–Co ferrites synthesized by Pechini method: Cation distribution and high temperature magnetic studies

This paper reports the influence of rare-earth (RE) doping on static and dynamic magnetic properties of 50-nm-thick Fe-Ga films grown on a glass substrate. With the addition of RE elements, the magnetic softness of Fe-Ga films improved at higher RE content, which might be attributed to the induction of in-plane uniaxial anisotropy by RE doping. As for the dynamic properties of Fe-Ga-RE films, an overall increased effective in-plane damping constant (α//,eff) were observed as the increase of RE content, except for a decreased α//,eff from 0.0228 to 0.0151 at low RE contents. These results suggest that the addition of RE could induce tunable magnetic properties in Fe-Ga films, making resultant Fe-Ga-RE films as one of the promising candidates for the sensing applications and high frequency microwave magnetic devices.

Effects of rare earth doping on multi-core iron oxide nanoparticles properties

Effect of rare earth doping on the vibrational spectra of spinel Mn-Cr ferrite

Effect of rare-earth doping on adsorption of carbon atom on ferrum surface and in ferrum subsurface: A first-principles study