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.

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.

Magnesium-Silicon Substituted Carbonate Hydroxyapatite (Mg-Si CHA): Factors Affecting Sintering

2016 ◽  
Vol 694 ◽  
pp. 88-93
Author(s):  
Ahmad Fauzi Mohd Noor ◽  
Harmiza Zainudin
Keyword(s):  
Mechanical Properties ◽  
Single Phase ◽  
Physical And Mechanical Properties ◽  
Major Effect ◽  
Carbonate Content ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
Complex Process ◽  
Powder Properties ◽  
Properties Of Materials

Sintering has major effect on the final properties of materials such as density, porosity and microstructure. Sintering of Mg-Si CHA in particular is a complex process since changes could occur during sintering, which include phase formation, grain size, pore size and carbonate content, and this in turn affects the mechanical properties. Improved mechanical properties of Mg-Si CHA is critical in load bearing implant applications. Poor control of thermal treatment of Mg-Si CHA during sintering would cause carbonate loss, leading to partial or total decomposition of Mg-Si CHA, subsequently would affect the physical and mechanical properties. The influence of powder properties (particle size, porosity, morphology) and sintering parameters (heating rate, firing atmosphere) on the sintered Mg-Si CHA microstructure was studied using scanning electron microscopy (SEM) characterization technique. The SEM results showed that we are able to produce sintered Mg-Si CHA without cracking of the compacted pellets, while keeping the carbonate level in the amount required (2 – 8%). X-Ray diffraction (XRD) was also performed on the sintered samples and the results indicated that a single phase Mg-Si-CHA was obtained, while Fourier transform infra-red (FTIR) spectroscopy result confirmed that as-synthesized Mg-Si CHA powder was a B-type.

Facile Mechanochemical Synthesis and Magnetic Properties of pervoskite YCrxFe1-xO3, (0≤x≤1).

2012 ◽  
Vol 1397 ◽  
Author(s):  
Vijayalaxmi MalagaReddy ◽  
Binod Rai ◽  
Sanjay Mishra ◽  
Chaunbing Rong ◽  
J Liu
Keyword(s):  
Single Phase ◽  
Magnetic Measurements ◽  
Hysteresis Loops ◽  
Chloride Salt ◽  
X Ray Diffraction ◽  
Mechanochemical Method ◽  
X Ray ◽  
Cr Content ◽  
Cr Doping ◽  
Fe Ions

ABSTRACTSingle-phase samples of YCrxFe1−xO3 were synthesized by a mechanochemical method. X-ray diffraction data show linear reduction in the lattice parameters of YCrxFe1−xO3 perovskites with the Cr content, indicating that Cr ions substitute for Fe ions to form a solid solution. Magnetic measurements show hysteresis loops at 5K. The substitution of Cr for Fe enhances the magnetization for up to x=0.33 Cr doping level. For higher doping levels, 0.33<x<1, the system behaves as a frustrated system. At x=1, YCrO3 behaves as a week ferromagnet with TN ~140 K. The chloride salt based machenochemical method offers simple synthesis route for the synthesis of pure multiferroic compounds.

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.

Structure and Magnetic Properties of Ga Substituted Ni-Ferrites

2013 ◽  
Vol 446-447 ◽  
pp. 68-72
Author(s):  
Ahmad Amirabadizadeh ◽  
Zobedeh Momeni Larimi ◽  
Saeideh Eghbali
Keyword(s):  
Magnetic Properties ◽  
Single Phase ◽  
Sol Gel ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
X Ray Diffraction ◽  
Auto Ignition ◽  
Transmission Electron ◽  
Magnetic Hysteresis Loops ◽  
Ga Content

Nanocrystalline Ga doped nickel ferrite [(NiFe2-xGaxO4 (x=0.0, 0.1, 0.3, 0.5 and 0.7)] powders have been synthesized by sol-gel auto-ignition method and the effect of non-magnetic gadillum content on the nanosize particles and magnetic properties has been studied. The X-ray diffraction (XRD) revealed that the powders obtained are single phase with spinel structure. The calculated grain size from XRD data have been verified using transmission electron microscopy (TEM). TEM photograph shows that the powders consist of nanometer sized grain. The size of nanoparticles decreases as the non magnetic Ga content increases. Magnetic hysteresis loops were measured at room temperature with maximum applied magnetic field of 20 KOe. As Ga content increases, the measured magnetic hysteresis curves became border and saturation magnetization (MS) increased up to x= 0.3 and further increase of x leads the magnetization to decrease. The results are explained according to the assumed cation distribution.

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.

scholarly journals Synthesis, structure and magnetic properties of Y3Fe5-xAlxO12 garnets prepared by the soft chemical method

2014 ◽  
Vol 8 (4) ◽  
pp. 211-218 ◽  
Author(s):  
Pedro Ortega ◽  
Miguel Ramirez ◽  
César Foschini ◽  
Filiberto Garcia ◽  
Mario Cilense ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Single Phase ◽  
Hysteresis Loops ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
Spin Effects ◽  
Transmission Electron ◽  
Surface Spin ◽  
Iron Garnet

A study was undertaken about the structural, morphological and magnetic properties at room temperature of crystalline aluminium substituted yttrium iron garnet, YIG (Y3Fe5-xAlxO12 with 1.5< x < 1.7) nanoparticles prepared by polymeric precursormethod at the temperature of 700?C for 2 hours. The single-phase character and the well-defined structure of YIG nanoparticles were confirmed by X-ray diffraction, excluding the presence of any other phases. The Raman spectra showed that the changes of lattice vibration would influence interaction between the Fe ion and the host. Mean crystallite size of the single-phase powder was about 46-65 nm. Particles? morphology was investigated by high-resolution transmission electron microscopy, which shows that the particles were agglomerated. From hysteresis loops, particles? efficiency range from 91.4% to 95.9% as Fe/Al ratio decreases. Saturation magnetization was affected by the particle size and Fe/Al stoichiometric ratio. We observe that the saturation magnetization increases as the Fe/Al ratio is raised due to enhancement of the surface spin effects.

Preparation and Characterization of Dielectric Behavior of A2/3Cu3Ti4O12 (A = Nd, Sm, Gd, Dy) Ceramics

2010 ◽  
Vol 67 ◽  
pp. 28-33 ◽  
Author(s):  
Dorota Szwagierczak ◽  
Jan Kulawik
Keyword(s):  
Single Phase ◽  
Elevated Temperatures ◽  
Relaxation Times ◽  
Dielectric Behavior ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Low Frequencies ◽  
Perovskite Materials ◽  
Very High

In this work perovskite materials A2/3Cu3Ti4O12 (where A=Nd, Sm, Gd, Dy) were synthesized by conventional solid state reaction and sintered at 1000-1100°C. X-ray diffraction analysis confirmed single-phase composition of the investigated ceramics. Dielectric properties of the samples were investigated in the temperature range from -55 to 300°C at frequencies 10 Hz – 2 MHz. Dielectric permittivities of the ceramics are very high, exceeding 105 at low frequencies and/or elevated temperatures (above 50°C) and 103 at higher frequencies and/or low temperatures. Two observed contributions to the dielectric response are attributed to semiconducting grains and more resistive grain boundaries. For Nd2/3Cu3Ti4O12 and Sm2/3Cu3Ti4O12 ceramics, the observed low- and high frequency plateaus are lower than those for Gd2/3Cu3Ti4O12 and Dy2/3Cu3Ti4O12. The relaxation times determined on the basis of impedance data were found to decrease with increasing atomic number of lanthanide. The analysis of the impedance spectroscopic data and the microstructure implies spontaneous formation of internal barrier layer capacitors in the investigated materials.

Phases and Thermoelectric Properties of Bulk NiSb2 and Composite of NiSb2 and CoSb3 Prepared by Sintering

2012 ◽  
Vol 503-504 ◽  
pp. 507-510 ◽  
Author(s):  
Ke Gao Liu ◽  
Nian Jing Ji ◽  
Zhong Quan Ma
Keyword(s):  
Thermoelectric Properties ◽  
Single Phase ◽  
Semiconductor Materials ◽  
Thermal Constant ◽  
X Ray Diffraction ◽  
X Ray ◽  
Seebeck Coefficients ◽  
Maximum Value ◽  
Type Semiconductor ◽  
Composite Samples

For researching the thermoelectric properties, bulk NiSb2 and the composite of CoSb3 and NiSb2 were prepared by sintering. The phases of samples were analyzed by X-ray diffraction and their thermoelectric properties were tested by electric constant instrument and laser thermal constant instrument. Experimental results show that, Bulk NiSb2 and the composite of NiSb2:CoSb3=2:8 and 4:6 were prepared by sintering at 600°C for 10min and they are N-type semiconductor materials with high densities of 6.998~7.142g/cm3. The bulk NiSb2 sample sintered is nearly single phase NiSb2, while the major phases of the composite of NiSb2:CoSb3=2:8 are major phase CoSb3 with impurity phase NiSb2. The electric resistivity of bulk NiSb2 sample increases with temperature rising while those of the composites (NiSb2:CoSb3=2:8 and 4:6) increase at 400~500 °C. The absolute values of Seebeck coefficients of the composite samples (NiSb2:CoSb3=2:8 and 4:6) increase with temperature rising and are evidently higher than those of bulk NiSb2. The power factors of the composites (NiSb2:CoSb3=2:8 and 4:6) are evidently higher than those of bulk NiSb2 while the power factor of NiSb2 sample varies not obviously with temperature rising, but those of the composites (NiSb2:CoSb3=2:8 and 4:6) increase with temperature rising and reaches the maximum value of 21.3 10-4Wk-2m-1 at 500 °C.

Effects of Ion Doping at Different Sites on Electrical Properties of Ferroelectric Bi4Ti3O12 Ceramics

2011 ◽  
Vol 399-401 ◽  
pp. 796-804
Author(s):  
Yun Yi Wu ◽  
Lei Wang ◽  
Zhi Qiang Hua ◽  
Tao Li ◽  
Xue Tao Yuan ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Single Phase ◽  
Hysteresis Loops ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ion Doping ◽  
Conventional Sintering ◽  
Ferroelectric Hysteresis ◽  
A Site ◽  
Co Doped

Pure, La3+doped at A site, V5+doped at B site, and La3+and V5+co-doped ferroelectric Bi4Ti3O12(BTO), Bi3.25La0.75Ti3O12(BLT), Bi4Ti2.98V0.02O3(BTV) and Bi3.25La0.75Ti2.98V0.02O12(BLTV) were successfully prepared by conventional sintering technique. The structures of the ceramics were investigated by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. X-ray diffraction indicated that assemblages of all sintered ceramics consist of a single phase of Bi4Ti3O12, implying that the A-site La3+and B-site V5+substitutions in this case do not affect the layered structure. Among these ceramics, BLTV ceramic exhibited the best electrical properties. The leakage current density of BLTV ceramic was only 1.3×10-4Acm-2at 40 KVcm-1, two orders of magnitude lower than BTO ceramic. Besides, a saturated ferroelectric hysteresis loops with largest remnant polarization 2Pr of 30.6μC/cm2was observed for this sample. These suggested that the co-doped Bi4Ti3O12ceramic by La3+and V5+at A and B sites showed advantages in application over the pure BTO, doped BLT and BTV ceramic, respectively.

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