Consolidation and characterization of highly dense single-phase Ta-Hf-C solid solution ceramics

2018 ◽  
Vol 102 (1) ◽  
pp. 58-62 ◽  
Author(s):  
Jian Zhang ◽  
Song Wang ◽  
Wei Li
Keyword(s):  
Solid Solution ◽  
Single Phase

Preparation and Characterization of Well-Dispersed Nd1.6Eu0.4Zr2O7 Solid Solution and its Fluorescent Behavior

2010 ◽  
Vol 97-101 ◽  
pp. 182-186
Author(s):  
Yu Ping Tong ◽  
Jing Wang ◽  
Rui Zhu Zhang ◽  
Shun Bo Zhao
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Room Temperature ◽  
Single Phase ◽  
Combustion Process ◽  
Crystal Form ◽  
Scherrer Formula ◽  
Xrd Patterns ◽  
Average Size

Well-dispersed Nd1.6Eu0.4Zr2O7 solid solutions were successfully prepared by a convenient salt-assisted combustion process using glycine as fuel. The samples were characterized by XRD, Raman, TEM and HRTEM. The results showed that the Nd ion can be partially replaced by Eu ion. The substituted product was still single-phase solid solutions and the crystal form remained unchanged. TEM images showed that the Nd1.6Eu0.4Zr2O7 solid solutions were composed of well-dispersed sphere-shaped nanocrystals with an average size of 30 nm, which is consistent with the value obtained from XRD patterns using the Scherrer formula. Moreover, the fluorescent characterization of the Nd1.6Eu0.4Zr2O7 nanocrystals at 385 nm upon excitation was carried out at room temperature, and the results showed that there were some intense and prevailing emission peaks located at 590-650 nm.

scholarly journals Synthesis and characterization of a solid solution series of the type Bi2MxMn4-xO10 (M = Cr3+, Co3+ and 0.0 ≤ x ≤ 2.0.)

2021 ◽  
Vol 45 (1) ◽  
pp. 13-26
Author(s):  
Aparna Sarker ◽  
AKM Lutfor Rahman ◽  
Tapas Debnath ◽  
Altaf Hussain
Keyword(s):  
Solid Solution ◽  
Single Phase ◽  
Synthesis Temperature ◽  
Nominal Composition ◽  
Solid Solution Series ◽  
Organic Precursor ◽  
Solution Series ◽  
Type Phase ◽  
Xrd Patterns

Bi2Mn4O10 was synthesized from corresponding metal salts in glycerin by using an organic precursor-based glycerin nitrate method. The precursor was heated at various temperatures (300 – 800 °C) for about 18 hours to determine the lowest synthesis temperature for the formation of Bi2Mn4O10. The XRD patterns of the calcined samples revealed that the desired mullite type phase started to form at 600 °C, which became more crystalline with further increase of calcination temperature. Attempts were also taken to prepare chromium and cobalt incorporated solid solution series with nominal composition Bi2MxMn4-xO10 (M = Cr3+ and Co3+) by the same procedure. The XRD data of these series exhibited mullite type single phase up to x = 0.7 and 0.1 compositions for chromium and cobalt, respectively. For further insertion of M, an extra phase appeared along with the mullite type phase. J. Bangladesh Acad. Sci. 45(1); 13-26: June 2021

Preparation and Characterization of Fine Indium Tin Oxide Powders by a Hydrothermal Treatment and Postannealing Method

2000 ◽  
Vol 15 (6) ◽  
pp. 1404-1408 ◽  
Author(s):  
K. Yanagisawa ◽  
C. P. Udawatte ◽  
S. Nasu
Keyword(s):  
Solid Solution ◽  
Hydrothermal Treatment ◽  
Tin Oxide ◽  
Indium Tin Oxide ◽  
Low Temperatures ◽  
Single Phase ◽  
Hydrothermal Processing ◽  
Hydrothermal Conditions ◽  
Oxide Powders

Indium tin oxide powder with an In to Sn mole ratio of 95:5 was successfully prepared from a coprecipitated In–Sn hydroxide gel by hydrothermal processing followed by calcination at relatively low temperatures (∼500 °C). Hydrothermal treatment of the In–Sn coprecipitated gel at 300 °C for 24 h led to the formation of a single phase of tin-doped indium oxyhydroxide (InOOH:Sn). Under hydrothermal conditions the oxyhydroxide phase appeared well crystallized with particles ∼80 nm in size. Calcination of the oxyhydroxide phase above 450 °C in air yielded a substitutional-vacancy-type solid solution of In2Sn1−xO5−y.

X-Ray Powder Diffraction Characterization of BaR2CuO5 (R=Yttrium and the Lanthanides) and Related Compounds

1989 ◽  
Vol 4 (1) ◽  
pp. 2-8 ◽  
Author(s):  
W. Wong-Ng ◽  
M.A. Kuchinski ◽  
H.F. McMurdie ◽  
B. Paretzkin
Keyword(s):  
Solid Solution ◽  
Cell Volume ◽  
Powder Diffraction ◽  
Single Phase ◽  
Crystallographic Data ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Related Compounds

AbstractA series of BaO:RxOy:CuO materials has been prepared where R=Y, La, Ce, Pr, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu. They have been characterized by X-ray powder diffraction methods. All BaR2CuO5 phases, commonly referred to as the “green phases”, are orthorhombic with space group Pbnm(62) and are isostructural. These single phase materials could be prepared with most lanthanides, except for La, Ce, Pr, Nd and Tb. Possible reasons for the exceptions are discussed. Both La and Nd tend to form a brown solid solution of Ba2+2xR4-2xCu2-xO10-2x with a tetragonal space group of P4/mbm(127). The major phases found in the Ce, Pr and Tb compositions are the perovskite-related structures BaRO3, and in the Pr case, Ba2PrCu3O6+x as well. The cell parameters of the green phase materials increase progressively from the Lu compound to the Sm compound: a ranges from 7.0506(6) to 7.2754(4) Å, b from 12. 0534(8) to 12. 4029(7) Å, c from 5.6099(5) to 5. 7602(3) Å, and the cell volume from 476.75(6) to 519.78(4) Å3. A correlation of the crystallographic data with the size of the R elements is given.

Effect of Calcination Conditions on Phase Formation and Characterization of BiFeO3-BaTiO3 Powders Synthesized by a Solid-State Reaction

2008 ◽  
Vol 55-57 ◽  
pp. 241-244 ◽  
Author(s):  
S. Chandarak ◽  
Thanapong Sareein ◽  
Athipong Ngamjarurojana ◽  
S. Maensiri ◽  
Pitak Laoratanakul ◽  
...  
Keyword(s):  
Solid Solution ◽  
Solid State ◽  
Phase Formation ◽  
Solid State Reaction ◽  
Single Phase ◽  
Vibrating Sample Magnetometer ◽  
Time Saving ◽  
First Time ◽  
Perovskite Type

A perovskite-type phase of solid solution of BiFeO3-BaTiO3 powders were synthesized by a solid-state reaction via a rapid vibro-milling technique. The effect of calcination condition on the phase formation, and characterization of BiFeO3-BaTiO3 powders were investigated. The formation of the BiFeO3-BaTiO3 phase investigated as a function of calcination conditions by TG–DTA and XRD. Morphology, particle size and chemical composition have been determined via a combination of SEM and EDX techniques and vibrating sample magnetometer (VSM) was used to characterize the structures and magnetic properties of prepared samples. The rapid vibro-milling is employed for the first time in this work as a significant time-saving method to obtain single-phase BiFeO3-BaTiO3 powders.

Preparation and Characterization of Lead-Free (Ba0.4Sr0.4Ca0.2)(Zr0.05Ti0.95)O3 Ceramics Using BST Seed Induced Method

2018 ◽  
Vol 766 ◽  
pp. 180-185
Author(s):  
Jiraporn Dangsak ◽  
Sukum Eitssayeam ◽  
Tawee Tunkasiri ◽  
Uraiwan Intatha
Keyword(s):  
Solid Solution ◽  
Solid State ◽  
Single Phase ◽  
Seed Crystal ◽  
Lead Free ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Seed Crystals

The solid solution of lead-free (Ba0.4Sr0.4Ca0.2) (Zr0.05Ti0.95) O3 (BSCZT) ceramics were prepared from the seed induced method. The Ba0.6Sr0.4TiO3 (BST) were used as the seed crystals, they were prepared using the molten salt technique. The phase formation was examined using the X-ray diffraction technique (XRD). It was found that the single phase perovskite structure of BST was obtained at a temperature of 800°C. The ceramics were prepared using the conventional solid state reaction by adding of BST seed crystals at 2.5, 5, 7.5 and 10 mol%. The structure showed that a single phase perovskite was obtained after sintered at 1400 °C. This work confirmed that BST seed crystal successfully diffused into BSCZT ceramic and the BSCZT ceramic with a seed crystal showed higher dielectric than the BSCZT ceramic without seed crystals.

Helium bubble formation in refractory single-phase concentrated solid solution alloys under MeV He ion irradiation

2021 ◽  
Vol 550 ◽  
pp. 152937
Author(s):  
N. Jia ◽  
Y. Li ◽  
H. Huang ◽  
S. Chen ◽  
D. Li ◽  
...  
Keyword(s):  
Solid Solution ◽  
Single Phase ◽  
Ion Irradiation ◽  
Bubble Formation ◽  
Helium Bubble

scholarly journals Fabrication and Characterization of Quinary High Entropy-Ultra-High Temperature Diborides

Ceramics ◽  
2021 ◽  
Vol 4 (2) ◽  
pp. 108-120
Author(s):  
Simone Barbarossa ◽  
Roberto Orrù ◽  
Valeria Cannillo ◽  
Antonio Iacomini ◽  
Sebastiano Garroni ◽  
...  
Keyword(s):  
High Temperature ◽  
Single Phase ◽  
Nominal Composition ◽  
High Entropy ◽  
Chemical Complexity ◽  
Alternative Processing ◽  
Plasma Sintering ◽  
High Temperature Synthesis ◽  
Spark Plasma

Due to their inherent chemical complexity and their refractory nature, the obtainment of highly dense and single-phase high entropy (HE) diborides represents a very hard target to achieve. In this framework, homogeneous (Hf0.2Nb0.2Ta0.2Mo0.2Ti0.2)B2, (Hf0.2Zr0.2Ta0.2Mo0.2Ti0.2)B2, and (Hf0.2Zr0.2Nb0.2Mo0.2Ti0.2)B2 ceramics with high relative densities (97.4, 96.5, and 98.2%, respectively) were successfully produced by spark plasma sintering (SPS) using powders prepared by self-propagating high-temperature synthesis (SHS). Although the latter technique did not lead to the complete conversion of initial precursors into the prescribed HE phases, such a goal was fully reached after SPS (1950 °C/20 min/20 MPa). The three HE products showed similar and, in some cases, even better mechanical properties compared to ceramics with the same nominal composition attained using alternative processing methods. Superior Vickers hardness and elastic modulus values were found for the (Hf0.2Nb0.2Ta0.2Mo0.2Ti0.2)B2 and the (Hf0.2Zr0.2Ta0.2Mo0.2Ti0.2)B2 systems, i.e., 28.1 GPa/538.5 GPa and 28.08 GPa/498.1 GPa, respectively, in spite of the correspondingly higher residual porosities (1.2 and 2.2 vol.%, respectively). In contrast, the third ceramic, not containing tantalum, displayed lower values of these two properties (25.1 GPa/404.5 GPa). However, the corresponding fracture toughness (8.84 MPa m1/2) was relatively higher. This fact can be likely ascribed to the smaller residual porosity (0.3 vol.%) of the sintered material.

A review on phase prediction in high entropy alloys

2021 ◽  
pp. 095440622110089
Author(s):  
Vinay Kumar Soni ◽  
S Sanyal ◽  
K Raja Rao ◽  
Sudip K Sinha
Keyword(s):  
Solid Solution ◽  
Phase Formation ◽  
Single Phase ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Modeling Tools ◽  
High Entropy ◽  
Recent Developments ◽  
Phase Prediction ◽  
The Stability

The formation of single phase solid solution in High Entropy Alloys (HEAs) is essential for the properties of the alloys therefore, numerous approach were proposed by many researchers to predict the stability of single phase solid solution in High Entropy Alloy. The present review examines some of the recent developments while using computational intelligence techniques such as parametric approach, CALPHAD, Machine Learning etc. for prediction of various phase formation in multicomponent high entropy alloys. A detail study of this data-driven approaches pertaining to the understanding of structural and phase formation behaviour of a new class of compositionally complex alloys is done in the present investigation. The advantages and drawbacks of the various computational are also discussed. Finally, this review aims at understanding several computational modeling tools complying the thermodynamic criteria for phase formation of novel HEAs which could possibly deliver superior mechanical properties keeping an aim at advanced engineering applications.

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