Microstructure and Phase Composition of Sputter-Deposited Zirconia-Yttria Films

1983 ◽  
Vol 30 ◽  
Author(s):  
R.W. Knoll ◽  
E.R. Bradley
Keyword(s):  
Phase Composition ◽  
Single Phase ◽  
Composition Range ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
Transmission Electron ◽  
Heat Treated ◽  
High Bias ◽  
Sputter Deposited

ABSTRACTThin ZrO2 -Y2 O3 coatings ranging in composition from 3 to 15 mole % Y2 O3 were produced by rf sputter deposition. This composition range spanned the region on the equilibrium ZrO2 -Y2O3 phase diagram corresponding to partially stabilized zirconia (a mixture of tetragonal ZrO2 and cubic solid solution). Microstructural characteristics and crystalline phase composition of as-deposited and heat treated films (1100°C and 1500°C) were determined by transmission electron microscopy (TEM) and by x-ray diffraction (XRD). Effects of substrate bias (0 ∼ 250 volts), which induced ion bombardment of the film during growth, were also studied. The as-deposited ZrO2-Y2O3 films were single phase over the composition range studied, and XRD data indicated considerable local atomic disorder in the lattice. Films produced at low bias contained intergranular voids, pronounced columnar growth, and porosity between columns. At high bias, the microstructure was denser, and films contained high compressive stress. After heat treatment, all deposits remained single phase, therefore a microstructure and precipitate distribution characteristic of toughened, partially stabilized zirconia appears to be difficult to achieve in vapor deposited zirconia coatings.

Microstructure and Phase Composition of (Ce, Mg)-PSZ Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 1194-1196
Author(s):  
Zhi Ping Shen ◽  
Shu Cai ◽  
Zhen Dong
Keyword(s):  
Heat Treatment ◽  
Phase Composition ◽  
Monoclinic Phase ◽  
Processing Method ◽  
Nanoporous Structure ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Partially Stabilized Zirconia ◽  
X Ray ◽  
Heat Treated

Magnesia, ceria partially stabilized zirconia (Ce,Mg)-PSZ ceramics with net shape microstructure are prepared using a processing method similar to that of conventional Mg-PSZ ceramics, then heat-treated at 1500°C for different time. Microstructure and phase composition of (Ce, Mg)-PSZ samples with different amount of CeO2 doped were investigated using SEM and X-ray diffraction. The addition of CeO2 could impede the formation of monoclinic phase and inhibit the growth of cubic grains. A microstructure with net-shape cubic grains, in which tetragonal precipitates interweave to a nanoporous structure is obtained by adding 4∼8 mol% CeO2 in 10mol% MgO doped zirconia matrix and then heat treatment at 1500°C for different time. The precipitate morophology might be related with the addition of CeO2 and the heat treatment temperatures.

Low Temperature Synthesis and Characterization of CaO and MgO- Stabilized Nanocrystalline Tetragonal Zirconia by Citrate Gel Process

2008 ◽  
Vol 368-372 ◽  
pp. 754-757
Author(s):  
Hasan Gocmez ◽  
Hirotaka Fujimori
Keyword(s):  
Single Phase ◽  
Tetragonal Zirconia ◽  
Xrd Analysis ◽  
Complex Method ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Heat Treated ◽  
Crystallite Sizes ◽  
Citrate Gel Process

The citrate gel method, similar to the polymerized complex method, was used to synthesize homogenous tetragonal zirconia at 800oC and 1000oC. Nanocrystalline tetragonal single phase has been fully stabilized with 3, 7, 10 mol% CaO and 10, 15 mol% MgO at 800oC, respectively. In addition, the XRD analysis showed the absence of monoclinic phase after addition of 7 and 10 mol% CaO into zirconia-based solid solutions, which have been fully stabilized both 800oC and 1000oC. The crystallite sizes of the t-ZrO2 with 3, 7 and 10 mol% CaO at 1000oC were 32, 28 and 29nm, respectively. For ZrO2- x mol% MgO (x=3, 10, 15) solid solution, the crystallite sizes of samples at 800oC were less than 29nm, however it was increased up to 69nm at 1000oC. The prepared gel and subsequent heat-treated powders were characterized by X-ray diffraction (XRD), Raman spectroscopy and transmission electron microscopy (TEM) to get detail information regarding to differentiation of polymorphs of zirconia as well as formation of powders.

scholarly journals Equimolar Yttria-Stabilized Zirconia and Samaria-Doped Ceria Solid Solutions

Ceramics ◽  
2018 ◽  
Vol 1 (2) ◽  
pp. 343-352 ◽  
Author(s):  
Reginaldo Muccillo ◽  
Daniel de Florio ◽  
Eliana Muccillo
Keyword(s):  
Tetragonal Phase ◽  
Room Temperature ◽  
Single Phase ◽  
Rietveld Analysis ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
Stabilized Zirconia ◽  
X Ray ◽  
Ceria Solid Solutions ◽  
Attrition Milling

Compositions of (ZrO2)0.92(Y2O3)0.08 (zirconia: 8 mol % yttria—8YSZ) and (CeO2)0.8(Sm2O3)0.2 (ceria: 20 mol % samaria—SDC20) ceramic powders were prepared by attrition milling to form an equimolar powder mixture, followed by uniaxial and isostatic pressing. The pellets were quenched to room temperature from 1200 °C, 1300 °C, 1400 °C and 1500 °C to freeze the defects configuration attained at those temperatures. X-ray diffraction analyses, performed in all quenched pellets, show the evolution of the two (8YSZ and SDC20) cubic fluorite structural phases to a single phase at 1500 °C, identified by Rietveld analysis as a tetragonal phase. Impedance spectroscopy analyses were carried out in pellets either quenched or slowly cooled from 1500 °C. Heating the quenched pellets to 1000 °C decreases the electrical resistivity while it increases in the slowly cooled pellets; the decrease is ascribed to annealing of defects created by lattice micro-tensions during quenching while the increase to partial destabilization of the tetragonal phase.

scholarly journals Nanocrystalline composites in TiO2 and SnO2 system for ammonia resistance sensors

2018 ◽  
Vol 12 (3) ◽  
pp. 240-247
Author(s):  
Anna Szczygielska ◽  
Zbigniew Pędzich ◽  
Wojciech Maziarz
Keyword(s):  
Phase Composition ◽  
Sol Gel ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Medium Size ◽  
X Ray Diffraction ◽  
Nanocrystalline Tio2 ◽  
Tio2 Anatase ◽  
Transmission Electron ◽  
Sorption Method

This work describes the production of nanocrystalline TiO2 and SnO2 oxides, as well as their nanocomposites (containing 26.9, 58.7 and 79.0wt.% of SnO2) with two-stage sol-gel method combined with high temperature treatment. The phase composition and medium size crystallites were determined using X-ray diffraction analysis (XRD) and revealed that the nanocomposites crystallize in tetragonal structures of TiO2 - anatase and SnO2 - cassiterite. Specific surface area of the nanopowders, measured using sorption method (BET), changed from 42.1 to 160.8m2/g. The morphology of the nanopowders was observed using transmission electron microscope (TEM). As indicated by TEM images, the manufactured nanopowders were well crystallized and consisted of small, spherical grains. The obtained nanopowders were also tested for NH3 gas detection application. The presented method of nanopowders synthesis enables to obtain nanocrystalline TiO2 and SnO2 oxides, as well as composites from TiO2-SnO2 of known and controlled chemical and phase composition. It also enables to obtain composites used for gas sensors. The sensor made of composite containing 58.7wt.% of SnO2 exhibited the best NH3 sensing features.

Corrosion Resistance of Partially Stabilized Zirconia Materials to Alkaline Steel Slag

2020 ◽  
Vol 852 ◽  
pp. 119-128
Author(s):  
Liang Zhao ◽  
Qian Huang ◽  
Hua Yin Sun ◽  
Xiang Li
Keyword(s):  
Corrosion Resistance ◽  
Steel Slag ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Stabilized Zirconia ◽  
Zirconia Powder ◽  
Slag Film ◽  
Partially Stabilized Zirconia ◽  
Stabilizing Agents ◽  
The Relationship

Partially stabilized zirconia (PSZ) materials were fabricated using 4 wt% CaO, 3 wt% MgO, and 5.4 wt% Y2O3 as stabilizing agents together with monoclinic zirconia powder. The physical properties, phase compositions, and microstructures of the Ca-PSZ, Mg-PSZ, and Y-PSZ samples were investigated by X-ray diffraction, scanning electron microscopy, and energy spectrum analysis. A crucible method was used to explore the relationship between the stabilizing agent and erosion resistance to alkaline steel slag. The results revealed that the zirconia materials stabilized by different stabilizing agents showed obvious differences in their bulk densities, apparent porosities, microstructures, and erosion resistances to alkaline steel slag. The structure of Y-PSZ showed highest density, containing a small number of uniformly distributed pores. In terms of Mg-PSZ, the intergranular bonding in its structure was observed to not be close, and the sample contained some cracks, but no pores. A large number of intragranular pores and a small number of overall pores was observed in Ca-PSZ, resulting in this material having the lowest bulk density. The pores and cracks provide the path to penetrate and diffuse for alkaline steel slag, which weakens the corrosion resistance of PSZ materials. The phase composition of the affected layers in all of the samples after corrosion was almost completely transformed from monoclinic phase to cubic phase, and the phase transition of both the original and transition layers was not obvious due to the formation of a slag film. Y-PSZ did not react with components of the steel slag such as SiO2 and Al2O3, showing the best corrosion resistance to alkaline steel slag.

Copper(I) Halide Nanoparticle-dispersed Glasses Prepared by Copper Staining

2005 ◽  
Vol 20 (9) ◽  
pp. 2480-2485 ◽  
Author(s):  
Kohei Kadono ◽  
Tatsuya Suetsugu ◽  
Takeshi Ohtani ◽  
Toshihiko Einishi ◽  
Takashi Tarumi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Surface Region ◽  
Borosilicate Glasses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Depth Profiles ◽  
Transmission Electron ◽  
Heat Treated ◽  
Glass Heat

Copper(I) chloride and bromide nanoparticle-dispersed glasses were prepared by means of a conventional copper staining. The staining was performed by the following process: copper stain was applied on the surfaces of Cl−- or Br−-ion-containing borosilicate glasses, and the glasses were heat-treated at 510 °C for various times. Typical exciton bands observed in the absorption spectra of the glasses after the heat treatment indicated that CuCl and CuBr particles were formed in the surface region of the glasses. The average sizes of the CuCl and CuBr particles in the glasses heat-treated for 48 h were estimated at 4.8 and 2.7 nm, respectively. The nanoparticles were also characterized by x-ray diffraction and transmission electron microscopy. Depth profiles of Cu and CuBr concentration in the glass heat-treated for 48 h were measured. Copper decreased in concentration monotonously with depth, reaching up to 60 μm, while the CuBr concentration had a maximum at about 25 μm in depth.

Effect of temperature on formation of murataite and murataite-pyrochlore ceramics

2002 ◽  
Vol 757 ◽  
Author(s):  
O. I. Kirjanova ◽  
S. V. Stefanovsky ◽  
S. V. Yudintsev
Keyword(s):  
Effect Of Temperature ◽  
Cold Crucible ◽  
Iron Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
Oxide Solid Solution ◽  
Transmission Electron ◽  
Heat Treated ◽  
Unit Cells ◽  
Fluorite Type

ABSTRACTProcesses of phases formation in the ceramic mixtures with basic compositions (wt.%) 10 CaO, 10 MnO, 5 Al2O3, 5 Fe2O3, 55 TiO2, 5 ZrO2, 10 UO2 (M1) and 8 CaO, 8 MnO, 4 Al2O3, 4 Fe2O3, 20 Gd2O3, 44 TiO2, 4 ZrO2, 8 UO2 (M4) were studied using X-ray diffraction, scanning and transmission electron microscopy. The batches were milled, compacted in pellets at 200 MPa, and heat-treated in a resistive furnace at 1100 °C, 1300 °C, 1400 °C, and 1500 °C as well as melted in a cold crucible at ∼1600 °C. Reactions in the mixtures heat-treated at 1100 °C were not completed and samples contained significant amount of unreacted and intermediate (altered rutile, cubic oxide solid solution, perovskite) phases. Within the temperature range 1100–1300 °C reactions are mainly completed and ceramics sintered at 1300 °C are composed of major murataite and minor rutile (M1) or major murataite and pyrochlore and minor zirconolite and perovskite (M4). However full homogenization at 1300 °C has not been reached yet and to obtain the ceramics with uniform compositions of the phases sintering at 1400 °C or melting at 1500–1600 °C were required.In the ceramic sample M1 two murataite varieties with five- (murataite-5C) and eight-fold (mu-rataite-8C) fluorite-type unit cells were found. The sample M4 is composed of pyrochlore, murataite-8C and zirconolite-3O. In the sample M1 murataite-5C is enriched with U and Ca and depleted with iron group elements as compared to murataite-8C. Fraction of murataite-5C concentrates about 80% of total U and about 70% of Mn+Fe (corrosion products). Waste elements partitioning among the phases in the M4 sample depends significantly on temperature of heat-treatment.

Preparation and Property of Al87Ce3Ni8.5Mn1.5 Nanophase Amorphous Composites

2011 ◽  
Vol 412 ◽  
pp. 263-266
Author(s):  
Hong Wei Zhang ◽  
Li Li Zhang ◽  
Feng Rui Zhai ◽  
Jia Jin Tian ◽  
Can Bang Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Phase ◽  
Volume Fraction ◽  
Material Structure ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Different Temperatures

The higher mechanical strength of Al87Ce3Ni8.5Mn1.5 nanophase amorphous composites has been obtained with two methods. The first nanophase amorphous composites are directly produced by the single roller spin quenching technology. The method taken for the second nanophase amorphous composites is at first to obtain amorphous single-phase alloy, followed by annealed at different temperatures .The formative condition, the microstructure, the particle size, the volume fraction of α-Al phase and microhardness of nanophase amorphous composites etc have been investigated and compared by X-ray diffraction (XRD) and transmission electron microscopy (TEM) and differential scanning calorimetry (DSC). The microstructure of composites produced by the second method is higher than the former, the fabricated material structure of the system is more uniform and the process is easier to control.

Direct Preparation of Ce0.8Sm0.2O1.9 Powders Oxidized With H2O2 for Low Temperature SOFCs Application

2005 ◽  
Author(s):  
Jianbing Huang ◽  
Zongqiang Mao ◽  
Bin Zhu ◽  
Lizhai Yang ◽  
Ranran Peng ◽  
...  
Keyword(s):  
Single Phase ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
Composite Electrolyte ◽  
Xrd Pattern ◽  
Transmission Electron ◽  
Direct Preparation ◽  
Novel Method ◽  
Power Densities

A novel method was developed to prepare fine doped ceria (DCO) powders directly. Ceria doped with 20 mol. % of samarium (Ce0.8Sm0.2O1.9, SDC) was prepared by in-situ oxidization of hydroxide precipitates with H2O2 in the solutions. The resultant powder desiccated at 85°C overnight was characterized by X-ray diffraction (XRD), thermogravimetry /differential thermal analysis (TG/DTA), and transmission electron microscopy (TEM). The XRD pattern showed that the as-dried SDC powder is single phase with a cubic fluorite structure like that of pure CeO2. An anode-supported SOFC was also fabricated based on SDC and 20wt. % (62mol. %Li2CO3–38 mol. %K2CO3) composite electrolyte, LiNiO2 as cathode and NiO as anode, by cold pressing. Using hydrogen as the fuel and air as the oxidant, the I-V and I-P characteristics exhibit excellent performances and the maximum power densities are about 696, 469, 377 and 240 mWcm−2 at 650, 600, 550 and 500°C, respectively.

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