Preparation of Zirconium Titanate Ceramics by Alloy Oxidation Method

2013 ◽  
Vol 634-638 ◽  
pp. 2402-2405 ◽  
Author(s):  
Wen Jie Yuan ◽  
Cheng Ji Deng ◽  
Hong Xi Zhu ◽  
Jun Li
Keyword(s):  
Single Phase ◽  
Pressureless Sintering ◽  
Zirconium Titanate ◽  
X Ray Diffraction ◽  
Homogeneous Microstructure ◽  
Oxidation Method ◽  
Bulk Ceramic ◽  
Maximum Value ◽  
Alloy Oxidation ◽  
Titanate Ceramics

In this paper, the investigations are presented for preparation of zirconium titanate ceramics by pressureless sintering of powders obtained by alloy oxidation method. ZrxTi1-xO2 (x=0.40-0.60) powders were prepared by the oxidation of Zr-Ti alloys. The zirconium titanate powders were sintered in the temperature range from 1400 to 1600 °C for 3 h by pressureless sintering. The relationships among the composition, the relative densities and microstructure of bulk ceramic were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show the sintering and microstructure of single phase zirconium titanate ceramics varied with ZrO2 content. The relative density of samples reaches the maximum value of near 92% when sintering temperature is up to 1600 °C. Irregular pores distributed uniformly among the particles in the sintered ceramics with homogeneous microstructure.

Nanocrystalline Barium Zirconium Titanate Synthesized by the Sonochemical Process

2013 ◽  
Vol 802 ◽  
pp. 119-123
Author(s):  
Supamas Wirunchit ◽  
Rangson Muanghlua ◽  
Supamas Wirunchit ◽  
Wanwilai Vittayakorn ◽  
Naratip Vittayakorn
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Reaction Time ◽  
Single Phase ◽  
Zirconium Titanate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Large Particles ◽  
Barium Zirconium Titanate ◽  
Scanning Electron

Nanocrystalline barium zirconium titanate, BaZr0.4Ti0.6O3, was synthesized successfully via the sonochemical process. The effects of reaction time on the precipitation of Ba(Zr,Ti)O3 particles were investigated briefly. The crystal structure as well as molecular vibrations and morphology were investigated. X-ray diffraction indicated that the powders exhibited a single phase perovskite structure, without the presence of pyrochlore or unwanted phases at the reaction time of 60 min. Nanocrystals were formed before being oriented and aggregated into large particles in aqueous solution under ultrasonic irradiation. A scanning electron microscopy (SEM) photograph showed the BZT powder as spherical in shape with uniform nanosized features.

STUDY OF STRUCTURAL, ELECTRICAL TRANSPORT AND MAGNETIC PROPERTIES IN La1-xAgxMnO3 COMPOUNDS

2004 ◽  
Vol 18 (05n06) ◽  
pp. 221-231 ◽  
Author(s):  
MANORANJAN KAR ◽  
S. RAVI
Keyword(s):  
Magnetic Field ◽  
Electrical Transport ◽  
Single Phase ◽  
Ac Susceptibility ◽  
X Ray Diffraction ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
Phase Form ◽  
X Ray ◽  
Maximum Value

X-ray diffraction, electrical resistivity and ac susceptibility measurements have been carried out on La 1-x Ag x MnO 3 compounds for x=0.05 to 0.30. These samples are found to be in single phase form with [Formula: see text] space group and with typical lattice parameters a=b=5.524Å and c=13.349Å for x=0.05 sample. The Mn–O–Mn bond angles and variance, σ2 are found to increase with doping. Metal-insulator transitions in the temperature range 254 to 259 K have been observed. These materials exhibit paramagnetic to ferromagnetic transitions in the vicinity of metal-insulator transition temperatures. The paramagnetic susceptibility could be analyzed using Curie–Weiss law. All the above samples exhibit colossal magneto-resistivity and its maximum value is found to be 73% for x=0.15 sample at 50 kOe magnetic field.

scholarly journals Magnetic and microwave absorption properties of nickel ferrite (NixFe3-xO4) by HEM technique

2017 ◽  
Vol 13 (3) ◽  
Author(s):  
Yunasfi Yunas ◽  
Wisnu Ari Adi ◽  
Mashadi Mashadi ◽  
Putri Astari Rahmy
Keyword(s):  
Nickel Ferrite ◽  
Single Phase ◽  
Magnetic Measurement ◽  
High Energy ◽  
Infrared Analysis ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
Absorption Properties ◽  
Microwave Absorption Properties ◽  
Maximum Value

Nickel ferrite (NixFe3-xO4) have been synthesized using solid state reaction with composition (2x)NiO : (3-x)Fe2O3 (x = 0.5; 1.0; 1.5 dan 2.0) in mol in wt%. Mixing of this powder was milled with HEM (High Energy Milling) for 10 hours, and then sintered at 1000 °C for 3 h. X-ray diffraction pattern indicates that the all of samples are single phase in this stage. FTIR (Fourier transform infrared) analysis showed two absorption bands in the range of ~410 - ~600 cm-1 related to octahedral and tetrahedral sites. The magnetic measurement using vibrating sample magnetometer (VSM) shows that the sample exhibited a ferromagnetic behaviour with its coercivity value in the range of 164-217 Oe, and the maximum value wasshowed by x =1.5. VNA (Vector Network Analyzer) characterization shows the ability electromagnetic wave absorption with RL (reflection loss) value of -28 dB occurs at frequency of 10.98 GHz. It means that the Ni1.5Fe1.5O4 sample can absorb microwave about ~96 % at 10.98 GHz.

Thermoelectric properties and microstructure of large-grain Mg2Sn doped with Ag

2009 ◽  
Vol 1166 ◽  
Author(s):  
Haiyan Chen ◽  
Nick Savvides
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Single Phase ◽  
Silver Content ◽  
X Ray Diffraction ◽  
Thermoelectric Power Factor ◽  
X Ray ◽  
Maximum Value ◽  
Vertical Bridgman ◽  
Scanning Electron

AbstractMg2Sn ingots, doped p-type by the addition of 0–1.0 at. % Ag, were prepared by the vertical Bridgman method at growth rates ∼0.1 mm/min. The crystalline quality and microstructure of ingots were analyzed by X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The single-phase Mg2Sn ingots consist of highly oriented large grains. Measurements of the Hall coefficient, Seebeck coefficient α, and electrical conductivity σ in the temperature range 80–700 K were conducted to study the dependence on the silver content, and to determine the thermoelectric power factor α2σ which reached a maximum value 2.4×10-3 W m-1 K-2 at 410 K for 1.0 at.% Ag content.

Pressureless Sintering of MoSi2 Materials

1994 ◽  
Vol 364 ◽  
Author(s):  
Roland Scholl ◽  
Thomas JÜngling ◽  
Bernd Kieback
Keyword(s):  
Phase Formation ◽  
Single Phase ◽  
Bending Strength ◽  
Milling Process ◽  
Full Density ◽  
Pressureless Sintering ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Powder Mixtures ◽  
Molybdenum Silicides

AbstractVarious powder mixtures were prepared by a modified mechanical alloying technique. Starting from elemental Mo-, Si- and C-powders the influence of milling conditions on phase formation during the milling process and the subsequent heat treatment was investigated. Phase formation during sintering and sintering kinetics of activated starting mixtures were studied by differential scanning calorimetry (DSC), thermal graphimetry (TG), X-ray diffraction (XRD) and dilatometry. The results show that phase formation during milling or sintering strongly depends on milling conditions. Optimized powder mixtures of single phase and reinforced molybdenum silicides show high densities up to 98,5 % TD by pressureless sintering in various atmospheres. Full density is possible by post-HIP because the samples show only closed porosity. The microstructure was studied in dependence of sintering parameters. The level of impurities, i.e. C, O2 was determined. Hardness, fracture toughness and bending strength were measured for single phase and particle reinforced materials.

Single Phase Ti2AlC Powder Synthesized from Ti-Al-0.6~0.9TiC-0.1Sn Mixture

2012 ◽  
Vol 512-515 ◽  
pp. 28-31 ◽  
Author(s):  
Meng Qi Li ◽  
Hong Xiang Zhai ◽  
Zhen Ying Huang
Keyword(s):  
High Purity ◽  
Single Phase ◽  
Reaction Path ◽  
Sintering Temperature ◽  
Structure Stability ◽  
Pressureless Sintering ◽  
Ratio Scale ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

A high purity of Ti2AlC powder has been synthesized by pressureless sintering a mixture of Ti-Al-TiC-Sn (Sn as an additive) powders. Four recipes with different mole ratios of Ti-Al-TiC-Sn were examined at sintering temperature from 1400°C to 1480°C. A high purity of Ti2AlC powder can be obtained by sintering all these four recipes at temperature 1450°C for 10 min in an Ar atmosphere. The synthesis of Ti2AlC on this large mole ratio scale of starting materials is associated with the evaporation of Al at high temperature and the structure stability of Ti2AlC. From the X-ray diffraction analysis, a reaction path for the Ti2AlC formation is proposed. Scanning electron microscopy was also used to characterize the samples.

Synthesize Ti3SiC2 from TiH2 by Pressureless Sintering

2012 ◽  
Vol 512-515 ◽  
pp. 676-680 ◽  
Author(s):  
Liang Li ◽  
Ai Guo Zhou ◽  
Li Bo Wang ◽  
Fei Xiang Hu
Keyword(s):  
Electron Microscopy ◽  
Single Phase ◽  
Argon Atmosphere ◽  
Pressureless Sintering ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
Titanium Silicon Carbide ◽  
X Ray ◽  
Titanium Silicon ◽  
Scanning Electron

In this paper, titanium silicon carbide (Ti3SiC2) powders were synthesized from TiH2 as Ti source by pressureless sintering in flowing argon atmosphere without preliminary dehydrogenation. Starting materials are powder mixtures with the mole ratio of 3TiH2/Si/2C or 3TiH2/SiC/C. Both kinds of starting materials were sintered in a tube furnace at the temperature range from 1300°C to 1500°C for 10~180min in flowing argon atmosphere. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to characterize the phase compositions and morphology of the products after different treatments. It was showed that almost single phase Ti3SiC2 powder (94.7 wt.%) can be synthesized by pressureless sintering from 3TiH2/Si/2C powders at 1400~1425°C for about 180min or from 3TiH2/SiC/C powders at 1425~1500°C for about 180min. From SEM micrographs, as-synthesized samples were porous. Most plate-like grains were about 5~10 μm in diameter and 1~2 μm in thickness. The speed of temperature increasing is an important factor to affect the purity of as-synthesized Ti3SiC2.

Dielectric and Piezoelectric Properties of Zirconium-Doped Bismuth Sodium Titanate Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 133-136 ◽  
Author(s):  
Anucha Watcharapasorn ◽  
Sukanda Jiansirisomboon
Keyword(s):  
Dielectric Constant ◽  
Single Phase ◽  
Sodium Titanate ◽  
Bismuth Sodium Titanate ◽  
X Ray Diffraction ◽  
Unit Cell Size ◽  
Systematic Shift ◽  
Titanate Ceramics ◽  
Dielectric And Piezoelectric Properties ◽  
Bismuth Sodium

Zirconium-doped bismuth sodium titanate ceramics were prepared using the conventional processing method. X-ray diffraction analysis indicated the materials were single phase with a systematic shift due to increased unit cell size. The measured densities and grain size of the ceramic samples were found to range from 5.79-6.03 g/cm3 and 0.5-1.6 µm, respectively. The dielectric constant as a function of temperature became broader as Zr content increased. The piezoelectric constant was found to decrease with increasing Zr. Within the range of the solid solutions investigated, the materials seem to be promising for high temperature applications where stable dielectric constant is required.

scholarly journals Magnetoelectric properties of materials based on barium zirconium titanate and various magnetic compounds

2021 ◽  
Vol 15 (3) ◽  
pp. 256-269
Author(s):  
Adis Dzunuzovic ◽  
Mirjana Vijatovic-Petrovic ◽  
Jelena Bobic ◽  
Nikola Ilic ◽  
Biljana Stojanovic
Keyword(s):  
Single Phase ◽  
Hysteresis Loops ◽  
Planetary Mill ◽  
Relaxation Processes ◽  
Zirconium Titanate ◽  
X Ray Diffraction ◽  
Properties Of Materials ◽  
Barium Zirconium Titanate ◽  
Very High ◽  
Composite Samples

Multiferroic composites containing ferroelectric Ba(Ti0.80Zr0.20)O3 (BT80Zr20) phase and magnetic Ni0.7Zn0.3Fe2O4 (NZF), CoFe2O4 (CF) or Ni0.7Cu0.01Sm0.05Zn0.29Fe1.95O4 (NCuSmZF) phase were investigated in this study. Three composites, BT80Zr20-NZF, BT80Zr20-CF and BT80Zr20-NCuSmZF were prepared by mixing chemically synthesized powders in the planetary mill, uniaxial pressing and sintering at 1300?C. X-ray diffraction data for the single phase and composites ceramics indicated the formation of crystallized structure of both ferrites and barium zirconium titanate, without the presence of undesirable phases. Microstructure analysis has shown the formation of two types of nanosized grains, polygonal ferromagnetic andd rounded ferroelectric grains. Non-saturated hysteresis loops were evident in all composite samples possibly due to the presence of very high conductive ferrite phases. The BT80Zr20-CF has shown the lowest conductivity values in comparison with other two compounds and therefore the highest potential for ferroelectric application. The impedance investigations confirmed the presence of different relaxation processes that originate from the grain and grain boundary contributions. Investigation of J-E relation between leakage and electric field for the BT80Zr20 and composites revealed the presence of four possible mechanisms of conduction in these materials.

Synthesis and Structural Characterization of Sol-Gel Derived Barium Zirconium Titanate Thin Films

2002 ◽  
Vol 718 ◽  
Author(s):  
A. Dixit ◽  
A. Savvinov ◽  
S.B. Majumder ◽  
R.S. Katiyar R. Guo ◽  
A.S. Bhalla
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Random Access ◽  
Zirconium Titanate ◽  
X Ray Diffraction ◽  
Homogeneous Microstructure ◽  
Single Crystalline ◽  
Crystalline Substrate ◽  
Wide Range ◽  
Barium Zirconium Titanate

AbstractBarium zirconium titanate (BZT) thin films are attractive candidates for dynamic random access memories and tunable microwave devices. In the present work a wide range of Zr doped BaTiO3 thin films have been prepared by sol-gel technique. X-ray diffraction and micro-Raman scattering studies confirmed the structural phases in the powder and film of BZT and various structural transitions of BaTiO3 as a function of different Zr content compared well with the published result on ceramics and single crystalline BZT. The deposited films had smooth, crackfree and homogeneous microstructure and Zr content has strong influence on the evolution of the microstructures of the films. Some selected compositions of these films were characterized in terms of their dielectric properties and phase transition behavior. BZT film with 20 at % Zr had a ferroelectric to paraelectric transition in the vicinity of room temperature. Efforts are underway to optimize the annealing condition and grow epitaxial BZT films, with various Zr contents, on a suitable single-crystalline substrate.

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