scholarly journals Ferroelectric and Dielectric Properties of Strontium Titanate Doped with Barium

Magnetism ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 22-36
Author(s):  
Ahmed Maher Henaish ◽  
Maha Mostafa ◽  
Ilya Weinstein ◽  
Osama Hemeda ◽  
Basant Salem
Keyword(s):  
Dielectric Properties ◽  
Temperature Dependence ◽  
Hysteresis Loops ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
Xrd Pattern ◽  
X Ray ◽  
Polarization Electric Field ◽  
Increasing Temperature ◽  
Tio2 Phase

Ferroelectric samples Sr1−xBaxTiO3 (BST), where x = 0, 0.2, 0.4, 0.6, 0.8 and 1, were prepared using the tartrate precursor method and annealed at 1200 °C for 2 h. X-ray diffraction, “XRD”, pattern analysis verified the structure phase. The crystallite size of the SrTiO3 phase was calculated to be 83.6 nm, and for the TiO2 phase it was 72.25 nm. The TEM images showed that the crystallites were agglomerated, due to their nanosize nature. The AC resistivity was measured as temperature dependence with different frequencies 1 kHz and 10 kHz. The resistivity was decreased by raising the frequency. The dielectric properties were measured as the temperature dependence at two frequencies, 1 kHz and 10 kHz. The maximum amount of dielectric constant corresponded to the Curie temperature and the transformation from ferroelectric to paraelectric at 1 kHz was sharp at 10 kHz. Polarization–electric field hysteresis loops for BST samples were measured using a Sawer–Tawer modified circuit. It was shown that the polarization decreased with increasing temperature for all samples.

Temperature Dependence of Linear Thermal Expansion of CuGaSe2 Crystals

2012 ◽  
Vol 725 ◽  
pp. 171-174
Author(s):  
Akira Nagaoka ◽  
Kenji Yoshino ◽  
Tomoyasu Taniyama ◽  
Hideto Miyake
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Linear Thermal Expansion ◽  
Secondary Phases ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Lattice Constants ◽  
Traveling Heater Method ◽  
Increasing Temperature

CuGaSe2 single crystals were grown by a traveling heater method, which is one of the solution growth techniques. The temperature dependence of the X-ray diffraction of CuGaSe2 was determined between 10 and 300 K. The room temeprature XRD pattern of CuGaSe2 corresponds to the ICDD data. No secondary phases are observed in the spectrum. The lattice constant of the a-axis increases and that of the c-axis decreases with increasing temperature. The linear thermal expansion of the c-axis calculated from the lattice constants indicates a negative value from 10 to 100 K.

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.

Influence of Magnetic Field on Magnetic Properties of Electrodeposited Co-Ni-P Nanowires

2014 ◽  
Vol 24 (3S1) ◽  
pp. 90-94 ◽  
Author(s):  
Le Tuan Tu ◽  
Luu Van Thiem ◽  
Pham Duc Thang
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Hysteresis Loops ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
X Ray ◽  
Structure And Morphology ◽  
The Magnetic Field

The magnetic properties in Co-Ni-P nanowires arrays with diameter of 200 nm were investigated. All the samples were prepared by electrodeposition method with pH of 5.5 and at room temperature. During the deposition, a magnetic field in range of 0 - 750 Oe was applied parallel to the wires axis. The crystalline structure and morphology of the samples were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM), respectively. The hysteresis loops were measured at room temperature using vibrating sample magnetometry (VSM). The mixture of hcp phases of the Co-Ni-P based nanowires has been indicated by the XRD pattern. The obtained results show that with 750 Oe magnetic field applied during deposition we can obtain maximum coercivity value (2180 Oe). The \(M_{r}/M_{s}\) ratio was rapid increased when the magnetic field changed from 0 Oe to 750 Oe.

Effect of Thermal Treatment on Dielectric Properties of 0.8Pb(Zr1/2Ti1/2)O3 - 0.2Pb(Co1/3Nb2/3)O3 Ceramics

2008 ◽  
Vol 55-57 ◽  
pp. 109-112
Author(s):  
Anurak Prasatkhetragarn ◽  
Supon Ananta ◽  
Rattikorn Yimnirun ◽  
David P. Cann
Keyword(s):  
Dielectric Properties ◽  
X Ray Diffraction ◽  
Precursor Method ◽  
Dielectric Characteristics ◽  
X Ray ◽  
Specific Composition ◽  
Cubic Phases ◽  
Treatment Conditions ◽  
Heat Treated ◽  
Formation Behavior

A combination between piezoelectric (Pb(Zr1/2Ti1/2)O3; PZT) and relaxor ferroelectric (Pb(Co1/3Nb2/3)O3; PCN) materials with a formula of 0.8Pb(Zr1/2Ti1/2)O3 - 0.2Pb(Co1/3Nb2/3)O3 has been prepared with solid-state reaction (the columbite-wolframite precursor method). This specific composition was selected for investigation because it is close to a morphotropic phase boundary (MPB) between the tetragonal and pseudo cubic phases. The phase formation behavior and microstructure were studied using x-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The dielectric properties of the compound were measured and discussed. The ceramics were also heat-treated at 800 oC. The results showed that the dielectric properties of the compound depended significantly on the heat treatment conditions. Most importantly, this study showed that the addition of PCN can improve the dielectric characteristics in PZT ceramics.

TEMPERATURE DEPENDENCE OF RELAXATION IN AlGaN/GaN HETEROSTRUCTURES

2007 ◽  
Vol 14 (04) ◽  
pp. 837-840
Author(s):  
Z. S. JIANG ◽  
W. ZHANG ◽  
Q. JI ◽  
J. XU ◽  
D. J. CHEN ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Tensile Strain ◽  
Lattice Strain ◽  
Passive Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Higher Temperature ◽  
The Difference ◽  
Increasing Temperature

Effects of Si 3 N 4 passivation layer on the lattice strain of Al 0.22 Ga 0.78 N layer with the thickness of 100 nm has been studied by in situ X-ray diffraction by the temperature range of 25°C–550°C. Results show that the temperature dependence of the strain relaxations can be separated into three linear regions. After passivation, an additional in-plane tensile strain is observed. The residual tensile strain increases with increasing temperature at low temperature, while at higher temperature the residual tensile strain decreases slightly. There is clear influence when a passive layer is deposited on the surface of the heterostructures. The linear regions in the temperature dependence of strain vary after the passive layer deposited on the heterostructure. These results indicate that the variation of the lattice strain relates to the difference in thermal stability between the epitaxy layer and the substrate.

STRUCTURAL, MAGNETIC AND DIELECTRIC PROPERTIES OF Fe-DOPED BaTiO3 SOLIDS

2012 ◽  
Vol 26 (09) ◽  
pp. 1250056 ◽  
Author(s):  
ZHENGANG GUO ◽  
LIHONG YANG ◽  
HONGMEI QIU ◽  
XUEDAN ZHAN ◽  
JINHUA YIN ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Photoelectron Spectroscopy ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Double Exchange ◽  
Exchange Interactions ◽  
Magnetic Element ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ferromagnetic Order

The structural, ferroelectric and magnetic properties of bulk perovskite Fe -doped BaTiO 3 (BFTO) prepared by standard solid-state reaction have been investigated. X-ray diffraction (XRD) identifies the tetragonal structure of BFTO samples. Rietveld refinements of XRD data indicates that the doping ions led to ab-plane expansion and out-of-ab-plane shrinkage of the BFTO phases. X-ray photoelectron spectroscopy (XPS) measurements for the prepared samples reveals that Fe 3+ and Fe 4+ ions replaces Ti 4+ ions in the crystal lattice to form single-phase BFTO solids. The results of the temperature-dependent dielectric properties and magnetic hysteresis loops for the BFTO solids show simultaneously the ferroelectric order and ferromagnetic order at room temperature. The doping of magnetic element Fe brings about ferromagnetic order for the samples, and the measured magnetic moment for each Fe atom increases from 0.70 μB to 1.55 μB in BFTO samples. The origin of ferromagnetism of the BFTO samples should be attributed to the double exchange interactions of Fe 3+– O 2– Fe 4+ ions.

FERROELECTRIC AND PIEZOELECTRIC PROPERTIES OF Gd3+ AND Y3+ MODIFIED PKN ELECTROCERAMICS

2008 ◽  
Vol 22 (15) ◽  
pp. 1515-1523
Author(s):  
K. SAMBASIVA RAO ◽  
D. MADHAVA PRASAD ◽  
P. MURALI KRISHNA ◽  
JOON HYUNG LEE
Keyword(s):  
Piezoelectric Properties ◽  
Hysteresis Loops ◽  
X Ray Diffraction ◽  
Reaction Route ◽  
X Ray ◽  
Polarization Electric Field ◽  
Solid State Reaction Route ◽  
Quality Factor Q ◽  
Ferroelectric And Piezoelectric Properties ◽  
Piezoelectric Constants

Ceramics with the composition Pb 1-x K 2x-3y M y Nb 2 O 6 (PKMN) with x = 0.29, y = 0.145 and M = Gd 3+, Y 3+ were synthesized by the solid-state reaction route between the corresponding oxides and carbonates. The crystal structure was confirmed by X-ray diffraction (XRD). The temperature dependence of dielectric properties were measured from 35 to 595°C. Well-developed P–E (polarization–electric field) hysteresis loops were observed in the materials. Determining the piezoelectric constants, Kp = 20%, Kt = 49%, d33 = 110, and quality factor, Qm = 33, reveals that the material Y 3+-modified PKN can be useful for transducer applications.

scholarly journals Colossal Permittivity and Low Dielectric Loss of Thermal Oxidation Single-Crystalline Si Wafers

Materials ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1102 ◽  
Author(s):  
Yalong Sun ◽  
Di Wu ◽  
Kai Liu ◽  
Fengang Zheng
Keyword(s):  
Dielectric Properties ◽  
Dielectric Loss ◽  
Thermal Oxidation ◽  
Crystalline Silicon ◽  
Single Crystalline Silicon ◽  
X Ray Diffraction ◽  
Xrd Pattern ◽  
Single Crystalline ◽  
X Ray ◽  
Low Dielectric

In this work, thin SiO2 insulating layers were generated on the top and bottom surfaces of single-crystalline silicon plates (n type) by thermal oxidation to obtain an insulator/semiconductor/insulator (ISI) multilayer structure. X-ray diffraction (XRD) pattern and scanning electron microscope (SEM) pictures implied that all of the synthesized SiO2 layers were amorphous. By controlling the thermal oxidation times, we obtained SiO2 layers with various thicknesses. The dielectric properties of silicon plates with different thicknesses of SiO2 layers (different thermal oxidation times) were measured. The dielectric properties of all of the single-crystalline silicon plates improved greatly after thermal oxidation. The dielectric constant of the silicon plates with SiO2 layers was approximately 104, which was approximately three orders more than that of the intrinsic single-crystalline silicon plate (11.9). Furthermore, both high permittivity and low dielectric loss (0.02) were simultaneously achieved in the single-crystalline silicon plates after thermal oxidation (ISI structure).

scholarly journals Dielectric Properties, AC Conductivity, and Electric Modulus Analysis of Bulk Ethylcarbazole-Terphenyl

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Hussam Bouaamlat ◽  
Nasr Hadi ◽  
Najat Belghiti ◽  
Hayat Sadki ◽  
Mohammed Naciri Bennani ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Ac Conductivity ◽  
Conduction Mechanism ◽  
Electric Modulus ◽  
X Ray Diffraction ◽  
X Ray ◽  
Universal Power Law ◽  
Electrical And Dielectric Properties ◽  
Increasing Temperature ◽  
Hopping Model

Electrical and dielectric properties for bulk ethylcarbazole-terphenyl (PEcbz-Ter) have been studied over frequency range 1 kHz–2 MHz and temperature range (R.T –120°C). The copolymer PEcbz-Ter was characterised by using X-ray diffraction. The frequency dependence of the dielectric constant (εr′) and dielectric loss (εr″) has been investigated using the complex permittivity. εr′ of the copolymer decreases with increasing frequency and increases with temperature. AC conductivity (σac) data were analysed by the universal power law. The behaviour of σac increases with increasing temperature and frequency. The change of the frequency exponent (s) with temperature was analysed in terms of different conduction mechanisms, and it was found that the correlated barrier-hopping model is the predominant conduction mechanism. The electric modulus was used to analyze the relaxation phenomenon in the material.

Temperature dependence of structure parameters in natural magnetite: single crystal X-ray studies from 126 to 773 K

1996 ◽  
Vol 52 (3) ◽  
pp. 450-457 ◽  
Author(s):  
H. Okudera ◽  
K. Kihara ◽  
T. Matsumoto
Keyword(s):  
Single Crystal ◽  
Temperature Dependence ◽  
Temperature Rise ◽  
Structural Parameters ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Dimensions ◽  
Increasing Temperature ◽  
Cation Sites

Structural parameters and their thermal changes in natural magnetite, Fe3O4, have been studied using the single-crystal X-ray diffraction method in the temperature range 126–773 K. The cell dimensions, oxygen coordinate and atomic mean square displacements (m.s.d.'s) reversibly change as a function of temperature. The coordinate of oxygen remains almost constant at x = 0.2549 (1) below ~600 K, but increases with increasing temperature above this temperature. This characteristic behavior of the oxygen coordinate with temperature indicates that the cation disordering over the tetrahedral (A) and octahedral (B) cation sites occurs above 600 K. All atomic m.s.d.'s increase monotonously with temperature rise. The m.s.d.'s of the B atom show a unique temperature dependence. At lower temperatures the B atom prefers to vibrate along [111], but this preference is reduced with a temperature rise up to 630 K, above which the m.s.d. normal to [111] becomes dominant.

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