scholarly journals Microstructural evolution and its influence on oxygen diffusion in yttrium-doped ceria thin films

2021 ◽  
Author(s):  
Jinzhan Li ◽  
Li Lei ◽  
Limin Li ◽  
Bo Deng ◽  
Gaoyang Zhao ◽  
...  
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Solid Oxide Fuel Cells ◽  
Oxygen Diffusion ◽  
Oxygen Vacancies ◽  
Fluorite Structure ◽  
Rare Earth Ions ◽  
Coated Conductors ◽  
Buffer Layers ◽  
Silicon Substrates

Abstract Ceria doped with rare earth ions (Ce1-xMxO2-y (y=x/2)), which contain many oxygen vacancies, have become excellent electrolyte materials for solid oxide fuel cells and important buffer layers for coated conductors. In this paper, Y3+ ions were doped into the lattice of CeO2 to form Ce1-xYxO2-y (CYO) thin films regarded as buffer layers to reduce oxygen diffusion on silicon substrates. It was revealed that the CYO films gradually transformed from a complete fluorite structure into a defective fluorite structure with more and more oxygen vacancies as the proportion of Y3+ ions in CYO films increased from zero, and then the defective fluorite structure transformed into rare earth C-type structure when the proportion of Y3+ ions was beyond 0.5. Moreover, at the beginning, the degree of oxygen diffusion showed an uptrend, but after the proportion of Y3+ ions reached a certain value, the degree of oxygen diffusion turned into a downtrend.

Engineered oxide thin films as 100% lattice match buffer layers for YBCO coated conductors

2003 ◽  
Vol 47 (12) ◽  
pp. 2171-2175 ◽  
Author(s):  
Y. Akin ◽  
Z.K. Heiba ◽  
W. Sigmund ◽  
Y.S. Hascicek
Keyword(s):  
Thin Films ◽  
Coated Conductors ◽  
Buffer Layers ◽  
Oxide Thin Films ◽  
Lattice Match ◽  
Ybco Coated Conductors

Deposition of rare earth tantalate buffers on textured Ni-W substrates for YBCO coated conductor using chemical solution deposition approach

2006 ◽  
Vol 21 (3) ◽  
pp. 767-773 ◽  
Author(s):  
M.S. Bhuiyan ◽  
M. Paranthaman ◽  
A. Goyal ◽  
L. Heatherly ◽  
D.B. Beach
Keyword(s):  
Rare Earth ◽  
Chemical Solution Deposition ◽  
Precursor Solution ◽  
Coated Conductors ◽  
Buffer Layers ◽  
Chemical Solution ◽  
Solution Deposition ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ybco Coated Conductors

Epitaxial films of rare-earth (RE = La, Ce, Eu, and Gd) tantalates, RE3TaO7 with pyrochlore structures were grown on biaxially textured nickel-3 at.% tungsten (Ni-W) substrates using chemical solution deposition (CSD) process. Precursor solution of 0.3∼0.4 M concentration of total cations were spin coated on to short samples of Ni-W substrates and the films were crystallized at 1050∼1100 °C in a gas mixture of Ar- 4% H2 for 15 to 60 min. X-ray studies show that the films of pyrochlore RE tantalate films are highly textured with cube-on-cube epitaxy. Improved texture was observed in case of lanthanum tantalate (La3TaO7) film grown on Ni-W substrates. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) investigations of RE3TaO7 films reveal a fairly dense and smooth microstructure without cracks and porosity. The rare-earth tantalate layers may be potentially used as buffer layers for YBa2Cu3O7-δ (YBCO) coated conductors.

scholarly journals Raman Study of Nanocrystalline-Doped Ceria Oxide Thin Films

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 432 ◽  
Author(s):  
Nursultan Kainbayev ◽  
Mantas Sriubas ◽  
Darius Virbukas ◽  
Zivile Rutkuniene ◽  
Kristina Bockute ◽  
...  
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Cerium Oxide ◽  
Oxygen Vacancies ◽  
Raman Shift ◽  
Size Factor ◽  
Doped Ceria ◽  
X Ray ◽  
Sio2 Substrate ◽  
Lower Frequencies

Samarium-doped ceria (SDC) and gadolinium-doped ceria (GDC) thin films were formed by e-beam vapor deposition on SiO2 substrate, changing the deposition rate and substrate temperature during the deposition. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-Ray spectrometry (EDS) were employed in order to investigate the structure ad morphology of the films. A single Raman peak describing the structure of undoped CeO2 was observed at a frequency of 466 cm−1. Doping of cerium oxide with rare-earth elements shifted the peak to lower frequencies (for Sm—462 cm−1). This shift occurs due to the increased number of oxygen vacancies in doped cerium oxide and it depends on the size and concentration factor of the dopant. It was found that wavenumbers and their intensity differed for the investigated samples, even though the peaks resembled each other in shape. The indicated bands for doped ceria originated as a result of the Raman regime (F2g) of fluorite dioxide associated with the space group (Fm3m). The observed peak‘s position shifting to a lower frequency range demonstrates the symmetric vibrations of oxygen ions around Ce4+ ions in octahedra CeO8. Raman shift to the lower frequencies for the doped samples has two reasons: an increase in oxygen vacancies caused by doping cerium oxide with rare-earth materials and the size factor, i.e., the change in frequency Δω associated with the change in the lattice constant Δa.

Improved Infrared Emissions of Er3+-Tm3+ Co-Doped Al2O3 Thin Films: The Role of Cross Relaxation Among Rare Earth Ions

2011 ◽  
Vol 11 (12) ◽  
pp. 10673-10676
Author(s):  
Bo Zhou ◽  
Zhisong Xiao ◽  
Lu Yan ◽  
Fang Zhu ◽  
Feng Zhang ◽  
...  
Keyword(s):  
Thin Films ◽  
Rare Earth ◽  
Cross Relaxation ◽  
Rare Earth Ions ◽  
Infrared Emissions ◽  
Co Doped

Improvement of the energy transfer from Ca3SnSi2O9host to rare-earth ions with the assistance of oxygen vacancies

RSC Advances ◽  
2014 ◽  
Vol 4 (2) ◽  
pp. 963-968 ◽  
Author(s):  
Xue Yu ◽  
Ting Wang ◽  
Xuhui Xu ◽  
Tingming Jiang ◽  
Hongling Yu ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Rare Earth ◽  
Oxygen Vacancies ◽  
Rare Earth Ions

Growth of rare-earth niobate-based pyrochlores on textured Ni–W substrates with ionic radii dependency

2005 ◽  
Vol 20 (4) ◽  
pp. 904-909 ◽  
Author(s):  
M.S. Bhuiyan ◽  
M. Paranthaman ◽  
S. Sathyamurthy ◽  
A. Goyal ◽  
K. Salama
Keyword(s):  
Rare Earth ◽  
Ionic Radius ◽  
Pyrochlore Structure ◽  
Precursor Solution ◽  
Deposition Process ◽  
Coated Conductors ◽  
Buffer Layers ◽  
Ionic Radii ◽  
Solution Deposition ◽  
Force Microscopy

Epitaxial films of rare-earth (RE) niobates, RE3NbO7 with pyrochlore structures, were grown on biaxially textured nickel–3 at.% tungsten (Ni–W) substrates using a chemical solution deposition process. A precursor solution of 0.3–0.50 M concentration of total cations was spin coated on to short samples of Ni–W substrates, and the films were crystallized at 1050–1100 °C in a gas mixture of Ar–4% H2 for 15 min. Detailed studies revealed that RE-niobates with ionic radius ratio RRE/RNb (R = ionic radius) from 1.23 to 1.40 (i.e., Sm, Eu, Gd, Ho, Y, and Yb) grow epitaxially with the pyrochlore structure. X-ray studies showed that the films of pyrochlore RE niobate films were highly textured with cube-on-cube epitaxy. Scanning electron and atomic force microscopy investigations of RE3NbO7 films revealed a fairly dense and smooth microstructure without cracks and porosity. The rare-earth niobate layers may be potentially used as buffer layers for YBa2Cu3O7−δ coated conductors.

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