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.

scholarly journals Epitaxial Growth and Multiferroic Properties of (001)-Oriented BiFeO3-YMnO3 Films

2015 ◽  
Vol 2 (3-4) ◽  
pp. 157-162
Author(s):  
Peng-Xiao Nie ◽  
Yi-Ping Wang ◽  
Ying Yang ◽  
Guo-Liang Yuan ◽  
Wei Li ◽  
...  
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Single Phase ◽  
Hysteresis Loops ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Leakage Currents ◽  
X Ray ◽  
Multiferroic Properties ◽  
Ferroelectric Hysteresis

Abstract In this paper, high-quality multiferroic (1-x)BiFeO3-xYMnO3 (x=0.05, 0.10, 0.15) thin films were successfully epitaxially grown on (001)SrTiO3 substrates with La0.67Sr0.33MnO3 buffered layers by pulsed laser deposition (PLD). X-ray diffraction shows the thin films are all single-phase perovskite with preferential orientation along the (001) direction. The (002) diffraction angles of thin films (from 0 to 0.15) shift to right, indicating the decrease of lattice parameters. All YMnO3-doped thin films exhibit strong upward self-poling via piezoelectric force microscope (PFM) measurement. Saturated ferroelectric hysteresis loops of thin films cannot be obtained even at the frequency of 50 kHz because of large leakage currents. It is noted that BFO-YMO thin films exhibit ferroelectricity considering the PFM and ferroelectric test. The magnetization measurements show that all BiFeO3-based films exhibit weak ferromagnetic behaviors with saturated magnetization at room temperature. The enhancement of magnetization was observed because of YMO doping, with the maximum saturation magnetization (M s) of 17.07 emu/cm3 in x=0.10 thin film.

Laser Sintering of Greens Compacts of MoSi2

2006 ◽  
Vol 530-531 ◽  
pp. 364-368
Author(s):  
G. de Vasconcelos ◽  
R. Cesar Maia ◽  
Carlos Alberto Alves Cairo ◽  
R. Riva ◽  
N.A.S. Rodrigues ◽  
...  
Keyword(s):  
Cross Section ◽  
Laser Processing ◽  
Single Phase ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heating Source ◽  
Scanning Electron Microcopy ◽  
Conventional Sintering ◽  
Reduced Time

In this study, the results of the feasibility of sintering green compacts of metallic powder of MoSi2 by a CO2 laser beam as the heating source has been investigated. The main advantage of this technique is to promote a dense material in a reduced time when compared to the conventional sintering process. In order to sintering the MoSi2 powder, green compacts of 6mm of diameter and 1.6mm thickness were produced in a steel die in a uniaxial press at 100MPa and after, isostatic pressed at 350MPa. The micrograph of the samples exposed to the laser radiation performed by scanning electron microcopy (SEM) reveal the efficiency of the sintering process and the X-ray diffraction of the powders confirmed the presence of single phase after and before laser processing. The average microhardness of these compacts reached near to 700 Hv0.2 in the cross section to the laser irradiation, indicating the all sintering of the green compact.

INFLUENCE OF SAMARIUM SUBSTITUTION ON IMPEDANCE DIELECTRIC AND ELECTROMECHANICAL PROPERTIES OF Pb(1-x)K2xNb2O6

2007 ◽  
Vol 21 (06) ◽  
pp. 931-945 ◽  
Author(s):  
K. SAMBASIVA RAO ◽  
P. MURALI KRISHNA ◽  
D. MADHAVA PRASAD ◽  
JOON HYUNG LEE
Keyword(s):  
Impedance Spectroscopy ◽  
Room Temperature ◽  
Single Phase ◽  
Piezoelectric Properties ◽  
Orthorhombic Structure ◽  
X Ray Diffraction ◽  
Electromechanical Properties ◽  
X Ray ◽  
Different Temperatures ◽  
Ferroelectric Hysteresis

Ferroelectric, hysteresis, impedance spectroscopy parameters, AC conductivity, and piezoelectric properties in the ceramics of Pb 0.74 K 0.52 Nb 2 O 6 and Pb 0.74 K 0.13 Sm 0.13 Nb 2 O 6 have been studied. X-ray diffraction study reveals single phase with the orthorhombic structure. The samples were characterized for ferroelectric and impedance spectroscopy properties from room temperature to 600°C. Cole–Cole plots (Z″ versus Z′) are drawn at different temperatures. The results obtained are analyzed to understand the conductivity mechanism in both the samples. The piezoelectric constant d33 has been found to be 96 × 10-12 C/N in PKN.

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.

MICRO-EMULSION METHOD FOR THE SYNTHESIS AND CHARACTERIZATION OF La, Mn-DOPED Ba3Co2 Fe24O41 Z-TYPE HEXA-NANOFERRITES

2019 ◽  
Vol 26 (10) ◽  
pp. 1950065
Author(s):  
GHULAM FARID ◽  
MUHAMMAD SAIF ◽  
GHULAM MURTAZA ◽  
ATIF HUSSAIN ◽  
MUHAMMAD UMAIR ◽  
...  
Keyword(s):  
Hysteresis Loops ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Emulsion Method ◽  
X Ray ◽  
Ion Doping ◽  
Micro Emulsion ◽  
X Ray Absorption ◽  
Mn Doped

In this report, micro-emulsion method was used to obtain La, Mn-doped Ba3Co2 [Formula: see text][Formula: see text] single-phase Z-type hexa-nanoferrites by maintaining annealing temperature at 1200∘C. X-ray diffraction (XRD) analysis shows lattice parameters, crystallite size, and volume are significantly enhanced by introducing La and Mn ions instead of Ba and Fe, respectively. Moreover, La and Mn ion doping improved the preferred orientation of atoms through the basal plane of Z-type hexaferrite. Field emission scanning electron microscopy (FESEM) study reveals that the surface morphology of La- and Mn-doped Ba3Co2 [Formula: see text][Formula: see text], Z-type ferrites show ultrafine and small particle size. The analysis of X-Ray absorption near edge spectroscopy (XANES) suggests that transition in [Formula: see text] has occurred from 3d core level to empty electronic state above the Fermi level. Furthermore, it is observed that in the Z-type ferrites Co exist as divalent ion and Fe as trivalent ion by analyzing XANES. Vibrating samples magnetometer (VSM) indicated that the samples are ferromagnetic as they have narrow hysteresis loops. The decrease in coercivity is due to paramagnetic dopant element Manganese (Mn).

scholarly journals Structural And Electrical Properties Of The Selected Rare-Earth Oxychlorides

2015 ◽  
Vol 60 (3) ◽  
pp. 1595-1602 ◽  
Author(s):  
M. Dziubaniuk ◽  
J. Wyrwa ◽  
M. Bućko ◽  
M. Rękas
Keyword(s):  
Rare Earth ◽  
Electrical Properties ◽  
Single Phase ◽  
Electrochemical Impedance ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Average Grain Size ◽  
Structural And Electrical Properties ◽  
Sintering Conditions

Abstract The preparation and sintering conditions of the selected rare-earth oxychlorides REOCl (Re=La, Nd, Sm, Gd) were determined. The purity of materials phase compositions was confirmed by X-ray diffraction method. Further analysis of the data enabled lattice parameters and average grain size determination. The electrical properties of the single phase REOCl materials were investigated by Electrochemical Impedance Spectroscopy in wide temperature range in atmospheric air. The spectra were analyzed by the equivalent circuit fitting. Basing on the values of equivalent circuits parameters the specific conductivities were calculated and presented in the Arrhenius coordinates. Energies of activation were calculated. The determined structural and electrical properties of four different rare-earth oxychlorides were directly compared.

scholarly journals Influence of N2 doping on photodective properties of p-typed Zn-N co-doped SnO2/n-Si heterojunction

2021 ◽  
Vol 5 (2) ◽  
pp. first
Author(s):  
Tran Le ◽  
Huu Phuc Dang
Keyword(s):  
Crystal Structure ◽  
Electrical Properties ◽  
Optical Sensors ◽  
High Sensitivity ◽  
Hole Mobility ◽  
X Ray Diffraction ◽  
Rutile Structure ◽  
X Ray ◽  
Co Doping ◽  
Co Doped

This work studied the effects of Zn and N co-doping on the crystal structure, electrical properties, and photoelectric effects of p-typed Zn-N co-doped SnO2/n-Si heterojunction. Zn and N co-doped SnO2 films (ZNTO) were deposited on n-type Si substrates at 300oC in different sputtering gas mixture Ar/N2 (% N = 0%, 30%, 50%, 60%, 70 % and 80%) from 5 wt% ZnO doped SnO2 target by the DC magnetron sputtering method. The crystal structure, surface morphology, chemical composition, electrical properties, and photoelectric effects of ZNTO films were investigated by measurements such as X-ray diffraction, FESEM, AFM, EDS, Hall, and I-V. The results showed that all films had a rutile structure, and the SnO2 (101) reflection was dominant on the optimal fabrication of 70% N2. Substitution of Sn4+ by Zn2+ and O2􀀀 by N3􀀀 were determined by the X-ray diffraction pattern (XRD) and X-ray energy scattering spectrum (EDS). The lowest resistivity for the ZNTO-5-70 film was r= 6.5010􀀀2 W.cmwith carrier concentration n = 1.461019 cm􀀀3 and hole mobility m = 6.52 cm2.V􀀀1.s􀀀1 respectively. I-V characteristics of the p – ZNTO – 5 – y/n – Si under the illumination condition showed the p-type electrical properties and their application as optical sensors. The ZNTO – 5 – y films' optical response current characteristic had high sensitivity and good reproducibility.

DIELECTRIC AND FERROELECTRIC PROPERTIES OF (Li, Ce)-DOPED Sr2Bi4Ti5O18 LEAD-FREE CERAMICS

2011 ◽  
Vol 01 (04) ◽  
pp. 439-445 ◽  
Author(s):  
QIAN CHEN ◽  
ZHIJUN XU ◽  
RUIQING CHU ◽  
YONG LIU
Keyword(s):  
Electrical Properties ◽  
Single Phase ◽  
Ferroelectric Properties ◽  
Lead Free ◽  
High Curie Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Lead Free Ceramics ◽  
Ce Modification

The influence of (Li, Ce) doping on the electrical properties of bismuth layer Sr 2-x (Li, Ce) x/2 Bi4Ti5O18 [abbreviated to SBTi-(Li, Ce) X/2] ceramics was investigated. X-ray diffraction analysis showed that all the ceramic samples were single-phase compounds. The (Li, Ce) modification significantly decreased the dielectric loss of Sr2Bi4Ti5O18 ceramics and greatly improved the piezoelectric activity. At x/2 = 0.0125, the SBTi-(Li, Ce) x/2 ceramics exhibited the excellent properties with high remnant polarization (P r = 9.3 μC/cm2) and high Curie temperature (T c = 299°C). Meanwhile, the SBTi-(Li, Ce)0.0125 ceramics had the largest piezoelectric constant (d33 = 26 pC/N). The results showed that the SBTi-(Li, Ce) x/2 ceramic was a promising lead-free piezoelectric material.

EFFECTS OF La DOPING ON FERROELECTRIC PROPERTIES OF CaBi4Ti4O15 THIN FILMS

2007 ◽  
Vol 14 (02) ◽  
pp. 277-281
Author(s):  
YANXIA DING ◽  
GUANGDA HU ◽  
SUHUA FAN
Keyword(s):  
Thin Films ◽  
Diffraction Analysis ◽  
Single Phase ◽  
Ferroelectric Properties ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
La Doping ◽  
Gel Technique ◽  
A Site

La modified CBTi ( CLBTi ) thin films were prepared on Pt/Ti/SiO 2/ Si (100) substrates by a sol–gel technique. X-ray diffraction analysis showed that single phase of CLBTi thin films were obtained. Their crystallization and hysteresis behavior were strongly dependent on the La contents. An increase of 2Pr as well as a decrease of 2Ec with the increase of La concentration were observed. The leakage properties of CBTi thin films were found to be improved by the La doping. The results were discussed with respect to the effects of La 3+ substitution at perovskite A-site.

scholarly journals EFFECTS OF Co DOPING ON PROPERTIES OF ILMENITE NiTiO3 CERAMICS

2018 ◽  
Vol 56 (1A) ◽  
pp. 119 ◽  
Author(s):  
Tran Tat Dat
Keyword(s):  
Raman Spectroscopy ◽  
Single Phase ◽  
Sol Gel ◽  
Nanocrystalline Powders ◽  
Rhombohedral Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Doping ◽  
Optical And Magnetic Properties ◽  
Co Doped

Pure and Co-doped NiTiO3 nanocrystalline powders were prepared by the sol-gel method. The effect of Co2+ doping on structural, optical and magnetic properties of NiTiO3 was investigated by X-ray diffraction, UV-vis absorption, Raman spectroscopy and vibration samples magnetometer. It was found that all fabricated samples were in single phase with rhombohedral structure. The presence of Co modifies the optical properties of the NiTiO3 nanocrystalline powders. Co doping in NiTiO3 resulted in decreasing of optical bandgap from 2.34 to 1.91 eV. The undoped and Co-doped samples

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