MULTIFERROIC MATERIALS Bi1-xSmxFeO3: A STUDY OF RAMAN AND ABSORPTION SPECTROSCOPIES

2010 ◽  
Vol 19 (02) ◽  
pp. 247-254 ◽  
Author(s):  
NGUYEN VAN MINH ◽  
DAO VIET THANG
Keyword(s):  
Lattice Dynamics ◽  
Optical Band Gap ◽  
Solid State Reaction Method ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Lattice Constants ◽  
Raman Measurement

Multiferroic Bi 1-x Sm x FeO 3(x = 0.00, 0.05, 0.1, 0.15, 0.2) ceramics were prepared by conventional solid state reaction method. X-ray diffraction measurement was carried out to characterize the crystal structure and to detect the impurities existing in these ceramics. The substitution of rare earth Sm for Bi was found to decrease the impurity phase in BiFeO 3 ceramics. There is strong evidence that both lattice constants a and c of the unit cell become smaller as the Sm 3+ content is increased. The effect of introducing Sm 3+ is shown to decrease the optical band gap for doped sample Bi 1-x Sm x FeO 3. Additionally, the temperature-dependent Raman measurement performed for the lattice dynamics study of Bi 1-x Sm x FeO 3 samples reveals a strong band centered at around 1000–1300 cm-1 which is associated with the resonant enhancement of two-phonon Raman scattering in the multiferroic Bi 1-x Sm x FeO 3 samples. This two-phonon signal is shown to broaden with increasing x. The Raman spectra at low wavenumbers are suggested to be related with magnon in this system.

scholarly journals Studies of phase transition and impedance behavior of Ba(Zr, Ti)O3 ceramics

2015 ◽  
Vol 05 (01) ◽  
pp. 1550002 ◽  
Author(s):  
P. Sateesh ◽  
J. Omprakash ◽  
G. S. Kumar ◽  
G. Prasad
Keyword(s):  
Phase Transition ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Phase Transition Behavior ◽  
Temperature Dependent ◽  
Conventional Solid State Reaction ◽  
Xrd Pattern ◽  
X Ray ◽  
Ceramic Samples ◽  
Barium Zirconium Titanate

Ceramic samples of Barium Zirconium Titanate ( BaZr x Ti 1-x O 3 ( BZT )) were synthesized by conventional solid-state reaction method with different concentrations of x(= 0.05 ( BZT1 ), 0.10 (BZT2), 0.15 (BZT3), 0.20 (BZT4), 0.25 (BZT5), 0.30 (BZT6)). Phase confirmation of the samples was done by X-ray diffraction (XRD) technique. All the compositions are in cubic structure. XRD pattern was recorded for samples sintered at different sintering temperatures. Lattice parameters increased with addition of Zr +4. Doping with Zr +4 into Barium titanate resulted in interesting changes of electrical properties (dielectric, impedance and ferroelectiricity). The strong influence of Zr doping on the phase transition characteristics of the BZT ceramics was studied from the dielectric response of the samples. Diffusivity of phase transition of the BZT ceramic samples increase with Zr +4 concentration, indicating changes from normal to diffuse transition to relaxor phase transition behavior. Impedance spectroscopy reveals the presence of temperature-dependent grain, grain boundary effects. Polarization–Electricfield (PE) loop measurements are also done on the samples.

Effect of cerium substitution on structural and impedance properties of 0.8Ba0.2(Bi0.5K0.5)TiO3lead free ceramic system

2016 ◽  
Vol 30 (06) ◽  
pp. 1650056
Author(s):  
M. N. V. Ramesh ◽  
K. V. Ramesh
Keyword(s):  
Impedance Analysis ◽  
Solid State Reaction Method ◽  
High Energy ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Lead Free Ceramics ◽  
A Site

Cerium-doped 0.8BaTiO3-0.2Bi[Formula: see text]K[Formula: see text]TiO3with composition 0.8Ba0.2(Bi[Formula: see text]K[Formula: see text])Ti[Formula: see text]Ce[Formula: see text]O3where x = 0.01, 0.02, 0.03, 0.04, 0.05, 0.06 lead free ceramics were prepared by conventional solid state reaction method followed by high energy ball milling. X-ray diffraction studies confirm the tetragonal structure at room temperature for all the Ce-doped samples. Lattice parameters and density were increasing with increase of Ce doping. Frequency and temperature dependent dielectric studies were carried out and indicate that the dielectric constant and Curie temperature are decreasing with increasing of Ce doping. All the Ce-doped samples exhibiting diffused and dispersive phase transitions with degree of diffuseness ranging from 1.4 to 2 calculated from the modified Curie–Weiss law. Impedance studies confirms the temperature dependent non-Debye kind of relaxation process in the material. From the Cole–Cole plots measured at high temperatures, reveals that the grain effect in the all Ce-doped samples. Impedance analysis studies also support the X-ray diffraction and dielectric studies that occupation of Ce both at A-site and B-site for small values of Ce doping.

Temperature Dependence on Dielectric Response of La0.7Ba0.3Mn0.4Ti0.6O3 Ceramic

2015 ◽  
Vol 1107 ◽  
pp. 45-52
Author(s):  
Aaliyawani Ezzerin Sinin ◽  
Walter Charles Primus ◽  
Abdul Halim Shaari ◽  
Zainal Abidin Talib ◽  
Sinin Hamdan
Keyword(s):  
Dielectric Properties ◽  
Temperature Dependence ◽  
Low Frequency ◽  
Sintered Sample ◽  
Solid State Reaction Method ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Low Frequencies ◽  
X Ray ◽  
Lcr Meter

Ceramic sample of La0.70Ba0.30Mn0.40Ti0.60O3 oxide has been prepared by the conventional solid-state reaction method. The sintered sample was characterized by using x-ray diffraction (XRD) and low frequency LCR meter. XRD result shows that the sample has a cubic structure with the existence of impurity phase. The dielectric properties of La0.70Ba0.30Mn0.40Ti0.60O3 measured from room temperature to 200°C shows that the dielectric permittivity is temperature dependence with strong dispersion at low frequencies. A circuit model based on the universal capacitor response function is also being used to represent the dielectric properties of the sample.

Photoluminescence properties of Na1.45La8.55(SiO4)6(F0.9O1.1):Eu for applications as a reddish orange phosphor

2014 ◽  
Vol 07 (05) ◽  
pp. 1450060 ◽  
Author(s):  
Qun Shi ◽  
Dhia A. Hassan ◽  
Renjie Zeng
Keyword(s):  
Spectral Analysis ◽  
Solid State Reaction Method ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
X Ray ◽  
Analysis System ◽  
Reddish Orange ◽  
The Eu

Europium-doped Na 1.45 La 8.55-8.55x( SiO 4)6( F 0.9 O 1.1)(0.000 ≤ x ≤ 0.045) phosphors were prepared by a conventional solid-state reaction method at 1200°C and their properties were studied by X-ray diffraction (XRD), and a spectral analysis system. No impurities were observed. The phosphor could be excited at 254 nm, 395 nm and 465 nm to yield a reddish orange emission which was attributed to the 5 D 0 → 7 F j (j = 0–2) transitions of the Eu ion.

Structural, dielectric, ferroelectric and impedance spectroscopic studies on Ba1−xSrxTiO3(0.15 ≤ x ≤ 0.35)

2019 ◽  
Vol 33 (17) ◽  
pp. 1950193 ◽  
Author(s):  
Shukdev Pandey ◽  
Om Parkash ◽  
Devendra Kumar
Keyword(s):  
Equivalent Circuit Model ◽  
Solid State Reaction Method ◽  
Spectroscopic Studies ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
X Band ◽  
Xrd Patterns ◽  
Diffuse Phase

Compositions with x = 0.15, 0.20, 0.25, 0.30 and 0.35 were synthesized in the system [Formula: see text] using conventional solid state reaction method and characterized by X-Ray Diffraction (XRD), Raman spectroscopy and Scanning Electron Microscopy (SEM). Tetragonal phase was confirmed in all the samples using Rietveld refinement of the XRD patterns and observation of their Raman spectra. Dielectric and impedance measurements were carried out in the temperature range 300–723 K in the frequency range 1 Hz to 1 MHz. The samples exhibit diffuse phase transition (DPT). Equivalent circuit model involving combination of Constant Phase angle Elements (CPE) and resistances (R) was developed which represents the data well. Expressions for the values of resistances (R) were established in terms of composition and temperature empirically. P-E loops indicated normal ferroelectric behavior for all the samples. Dielectric constant was also measured in the frequency range 8–12 GHz in the X band of microwaves.

Structural and Dielectric Analysis of La0.88Bi0.12Mn0.80Ni0.20O3 Composite

2021 ◽  
Vol 317 ◽  
pp. 35-45
Author(s):  
Aaliyawani Ezzerin Sinin ◽  
Walter Charles Primus ◽  
Zainal Abidin Talib ◽  
Chen Soo Kien ◽  
Abdul Halim Shaari ◽  
...  
Keyword(s):  
Dielectric Loss ◽  
Sintering Temperature ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Rhombohedral Structure ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
A Value ◽  
Electric Behavior

Composite La0.88Bi0.12Mn0.80Ni0.20O3 was synthesized using the conventional solid-state reaction method with sintering temperature of 1200 °C for 12 hours and the dielectric properties investigated. The X-ray diffraction result shows that the composite has a rhombohedral structure with lattice parameter of a = b = c = 5.5136 Ǻ. Scanning electron microscope shows grains with approximately from 0.8 to 5.4 μm in size with presence of voids. The dielectric permittivity, εʹ and dielectric loss, εʺ were measured in the range of 298 K to 473 K where both are temperature and frequency dependent. At 1 kHz to 100 kHz, the εʹ is around 10000 and the dielectric loss tangent, tan δ is below 1.5. The electric behavior of this composite is best represented by Quasi-dc model which consists of two universal capacitors in parallel. Parameters value from the fitting indicated that high correlations of electrons between inter and intra-clusters. The activation energy, Ea calculated from the conductivity of the sample gives a value of 0.116 eV. Vibrating sample magnetometer shows that the La0.88Bi0.12Mn0.80Ni0.20O3 has a magnetic coercivity, Hc of 36.109 G and retentivity, Br, valued 2.7504 x 10-3 emu/g.

Synthesis and Characterization of Low Density Bi-2223 Cuprates Superconductor Doped Eu2O3 Nanoparticles

2021 ◽  
Vol 317 ◽  
pp. 131-137
Author(s):  
Suhaimi Nurbaisyatul Ermiza ◽  
Azhan Hashim ◽  
Azman Kasim ◽  
Norazila Ibrahim ◽  
Siti Fatimah Saipuddin
Keyword(s):  
Solid State Reaction Method ◽  
Synthesis And Characterization ◽  
Crystallographic Structure ◽  
Low Density ◽  
Superconducting Properties ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Resistivity Measurements

Bi1.6Pb0.4Sr2Ca2-xEuxCu3Oδ cuprates superconductor doped with Eu nanoparticles (x = 0.0000, 0.0025, 0.0200 and 0.0500) were synthesized through conventional solid state reaction method. Crystalline sucrose was added during pelletization and burn at 400°C for two hours to create low density sample. The effect of doping Eu2O3 nanoparticles on the structural and superconducting properties by means of critical temperature (Tc), critical current density (Jc), X-ray diffraction (XRD) together with Field Emission Scanning Electron Microscopy (FESEM) and Alternating Current Susceptibility (ACS) were studied. Based on XRD analyses, the crystallographic structure has shown slightly changed from tetragonal to orthorhombic. The amount of 2223 phase gradually decreased with the increment of Eu concentration which indicates that Eu nanoparticles substitution favours the growth of 2212 phases. The resistivity measurements show that the highest Tcvalue for doped samples found at 90 K for x = 0.0025. The FESEM images showed that the plate-like grains become smaller and distributed randomly without specific alignment due to the increment of Eu concentration.

Electrical Properties of a High-Tc Superconductor-Polymer Compersite

2007 ◽  
Vol 546-549 ◽  
pp. 1989-1992
Author(s):  
Fang Gao Chang ◽  
Kun Fang ◽  
Gui Lin Song
Keyword(s):  
Annealing Temperature ◽  
Solid State Reaction Method ◽  
Gravimetric Analysis ◽  
Superconducting Transition ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Different Temperatures ◽  
Zero Resistance ◽  
Composite Samples

A superconductor-polymer composite of Bi1.8Pb0.4Sr2Ca2Cu3Oy and ethylene propylene rubber (EPR) was prepared by conventional solid-state reaction method. The phase structure of the composite was characterized by using x-ray diffraction technique. The resistivity of composite samples annealed at different temperatures was measured between 40K and 300K. The results indicate that the resistivity of the as-prepared composite increases with increasing EPR content and shows essentially a semiconducting behavior above Tc. For fixed EPR content, the resistivity of composite samples decreases with increasing annealing temperature. The composite begins to show some signs of superconducting transition at an annealing temperature of 700 °C and zero resistance is reached for samples sintered at 800°C. Thermal gravimetric analysis (TGA) on the composite confirmed that 65% of the EPR content still present in the superconducting composite samples. SEM was used to investigate the surface morphology of the composites. Preliminary results show that the mechanical properties of the composite have been much improved compared with its parent superconductor ceramics.

SYNTHESIS OF Ru1-xSbxSr2(Eu0.7Ce0.3)2Cu2O10-δ AND THEIR MAGNETIC AND TRANSPORT PROPERTIES

2005 ◽  
Vol 19 (22) ◽  
pp. 3511-3517 ◽  
Author(s):  
T. R. YANG ◽  
G. ILONCA ◽  
F. BEIUŞAN ◽  
A. V. POP ◽  
V. TOMA ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
Hall Effect ◽  
Exchange Coupling ◽  
Solid State Reaction Method ◽  
Band Model ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
X Ray ◽  
Two Band Model ◽  
Hole Localization

Ru 1-x Sb x Sr 2( Eu 0.7 Ce 0.3)2 Cu 2 O 10-δ systems were prepared by conventional solid state reaction method. The structural analysis was investigated using X-ray diffraction. Electrical resistivity, Hall effect and magnetic susceptibility measurements on Ru :1222 doped with Sb are presented, together with results in the temperature range 5–300 K. Transition temperature decreases from 43 K for x = 0.00 to 20 K for x = 0.06 Sb . This may be due to a distortion of RuO 6 octahedral, which is responsible of the increase in hole localization. The Hall effect anomalous decreases below T magnetic which may be explained within a simple two-band model by a transition from localized to more itinerant behavior in the RuO 2 layer at T magnetic . The behavior of magnetic susceptibility is caused by an antisymmetric exchange coupling of the Dzyaloshinsky–Morya type between neighboring Ru moments.

Study of Crystal Structural about La2/3(Ca(1-X)ZnX)1/3MnO3

2012 ◽  
Vol 535-537 ◽  
pp. 1031-1034
Author(s):  
Yong Xin ◽  
Guo Yun Chen ◽  
Cheng Hong Luo ◽  
Xin Fa Deng ◽  
Ling Yan Hu
Keyword(s):  
Bond Angle ◽  
Rietveld Method ◽  
Solid State Reaction Method ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Lattice Constants ◽  
Zn Content ◽  
Crystal Structural

Some samples of La2/3(Ca(1-x)Znx)1/3MnO3 （x = 0, 0.2, 0.4, 0.6, 0.8, 1.0） were prepared by solid-state reaction method at 1623K. The crystal structures of the compounds were studied by X-Ray Diffraction(XRD). All the samples are orthorhombic structure (Pnma), the symmetry has no obvious change with the increase of Zn atom content x. The crystal lattice constants, Mn-O bond length and Mn-O-Mn bond angle varied with the different Zn content, analyzed by the Rietveld method.

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