scholarly journals Characterization of nickel doped Zn7Sb2O12 spinel phase using Rietveld refinement

2003 ◽  
Vol 18 (3) ◽  
pp. 219-223 ◽  
Author(s):  
L. Gama ◽  
C. O. Paiva-Santos ◽  
C. Vila ◽  
P. N. Lisboa-Filho ◽  
E. Longo
Keyword(s):  
Crystal Structure ◽  
Rietveld Refinement ◽  
Spinel Phase ◽  
Pechini Method ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
Inverse Spinel ◽  
Precursor Method ◽  
X Ray

Zn7Sb2O12 is known to adopt an inverse spinel crystal structure, in which Zn2+ occupies the eight tetrahedral positions and Sb5+ and Zn2+ randomly occupy the 16 octahedral positions. Samples of Zn7−xNixSb2O12 (x=0, 1, 2, 3, and 4) were synthesized using a modified polymeric precursor method, known as the Pechini method. The crystal structure of the powders was characterized by Rietveld refinement with X-ray diffraction data. The results show that for x=0, 1, and 2 Ni substitutes for Zn2+ in the octahedral sites, and that for x=3 and 4 it is assumed that Ni2+ replaces Zn2+ ions in both the octahedral and tetrahedral positions. It is also observed for x=3 and 4 the formation of two spinel phases.

Preparation and Characterization of Pb(Zr,Ti)O3 Obtained by the Pechini Method

2018 ◽  
Vol 912 ◽  
pp. 97-101
Author(s):  
Raphael Cons Andrades ◽  
Antônio Hortencio Munhoz Jr. ◽  
Leila Figueiredo de Miranda ◽  
Renata Ayres Rocha
Keyword(s):  
Lead Zirconate Titanate ◽  
Pechini Method ◽  
Lead Nitrate ◽  
Lead Zirconate ◽  
Polymeric Precursor ◽  
X Ray Diffraction ◽  
Zirconyl Nitrate ◽  
X Ray ◽  
Scanning Electron

The aim of this work was to synthesize lead zirconate titanate, Pb(Zr0.52Ti0.48)O3 (PZT) via Pechini method, to characterize the polymeric precursor through differential thermal analysis and thermogravimetric analysis, as well as to characterize the PZT powder through x-ray diffraction and scanning electron microscopy with energy-dispersive spectroscopy. In this work, the metallic precursors used during the PZT synthesis were titanium IV isopropoxide, zirconyl nitrate and lead nitrate; citric acid and ethylene glycol were used as chelating and polymerizing agents, respectively. The polymeric precursor was calcined at 800°C for two hours in a muffle oven. The main results showed that the polymeric precursor undergoes decomposition at approximately 316°C and PZT is crystallized around 722°C. It was confirmed that the PZT powder has chemical composition in the morphotropic phase boundary and its morphology consists of agglomerates of particles. Finally, it was proved that the PZT powder is crystalline, with the predominance of the tetragonal phase.

X-ray powder diffraction data of LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites

2021 ◽  
pp. 1-6
Author(s):  
Mariana M. V. M. Souza ◽  
Alex Maza ◽  
Pablo V. Tuza
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Pechini Method ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Modified Pechini Method ◽  
Scanning Electron

In the present work, LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites were synthesized by the modified Pechini method. These materials were characterized using X-ray fluorescence, scanning electron microscopy, and powder X-ray diffraction coupled to the Rietveld method. The crystal structure of these materials is orthorhombic, with space group Pbnm (No 62). The unit-cell parameters are a = 5.535(5) Å, b = 5.527(3) Å, c = 7.819(7) Å, V = 239.2(3) Å3, for the LaNi0.5Ti0.45Co0.05O3, a = 5.538(6) Å, b = 5.528(4) Å, c = 7.825(10) Å, V = 239.5(4) Å3, for the LaNi0.45Co0.05Ti0.5O3, and a = 5.540(2) Å, b = 5.5334(15) Å, c = 7.834(3) Å, V = 240.2(1) Å3, for the LaNi0.5Ti0.5O3.

Synthesis and Characterization of Multiferroic NiFe2O4/BiFeO3 Nanocomposites by Modified Pechini Method

2011 ◽  
Vol 197-198 ◽  
pp. 456-459
Author(s):  
Xian Ming Liu ◽  
Wen Liang Gao
Keyword(s):  
Pechini Method ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Magnetic Bias ◽  
Field Frequency ◽  
Magnetic Field Frequency ◽  
X Ray ◽  
Structure And Morphology ◽  
Modified Pechini Method

Spinel-perovskite multiferroics of NiFe2O4/BiFeO3 nanoparticles were prepared by modified Pechini method. The structure and morphology of the composites were examined by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that the composites consisted of spinel NiFe2O4 and perovskite BiFeO3 after annealed at 700°C for 2h, and the particle size ranges from 40 to 100nm. VSM and ME results indicated that the nanocomposites exhibited both tuning magnetic properties and a ME effect. The ME effect of the nanocomposites strongly depended on the magnetic bias and magnetic field frequency.

scholarly journals PECHINI SYNTHESIS AND CHARACTERIZATION OF Eu3+ DOPED ZnCo2O4 SPINELS

2005 ◽  
Vol 03 (2) ◽  
pp. 24-29
Author(s):  
P.M. PIMENTEL ◽  
A.M.G. PEDROSA ◽  
H.K.S. SOUZA ◽  
C.N.S. JÚNIOR ◽  
R.C.A. PINTO ◽  
...  
Keyword(s):  
Spinel Structure ◽  
Pechini Method ◽  
Synthesis Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spinel Oxides ◽  
Diffraction Patterns ◽  
Pechini Synthesis ◽  
Spinel Structures

Spinel oxides with the composition ZnCo2O4 and ZnCo2O4:Eu3+ have been synthesized by the Pechini method and characterized by X-ray diffraction, infrared spectroscopy, thermal analysis and scanning electron microscopy. IR spectroscopy revealed the presence of n1 and n2 bands, typical of spinel structures. The formation of monophase cubic spinel structure was confirmed by X-ray diffraction patterns. Extra lines corresponding to other phase has been observed in the powders calcined at 900 ºC. The results showed the extremely lower synthesis temperature than those presents in conventional methods.

scholarly journals Structural and morphological characterization of rare earth modified lead titanate

Cerâmica ◽  
2007 ◽  
Vol 53 (328) ◽  
pp. 422-447
Author(s):  
F. C. D. Lemos ◽  
D. M. A. Melo ◽  
P. S. de Lima ◽  
C. A. Paskocimas ◽  
E. Longo ◽  
...  
Keyword(s):  
Rare Earth ◽  
Lead Titanate ◽  
Pechini Method ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Crystallite Sizes ◽  
Modifier Cation

Rare earth modified lead titanate powders Pb1-xRExTiO3 (REPT), x = 0.01, 0.05, 0.07 and RE = Yb, Y, were prepared by the Pechini method. The materials were calcined under flowing oxygen at different temperatures from 300 to 700 ºC. Nanostructured REPT were investigated using X-ray diffraction, scanning electron microscopy and surface area analysis (BET). The results suggest that the modifier cation incorporated into the system has notable influence in the microstructure and a notable decrease in the crystallite sizes.

scholarly journals Serendipitous formation and characterization of K2[Pd(NO3)4]·2HNO3

2019 ◽  
Vol 74 (4) ◽  
pp. 381-387
Author(s):  
Michael Zoller ◽  
Jörn Bruns ◽  
Gunter Heymann ◽  
Klaus Wurst ◽  
Hubert Huppertz
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Monoclinic Space Group ◽  
Solvothermal Process ◽  
X Ray Diffraction ◽  
Glass Ampoule ◽  
Space Group ◽  
X Ray ◽  
Complex Anions

AbstractA potassium tetranitratopalladate(II) with the composition K2[Pd(NO3)4] · 2HNO3 was synthesized by a simple solvothermal process in a glass ampoule. The new compound crystallizes in the monoclinic space group P21/c (no. 14) with the lattice parameters a = 1017.15(4), b = 892.94(3), c = 880.55(3) Å, and β = 98.13(1)° (Z = 2). The crystal structure of K2[Pd(NO3)4] · 2HNO3 reveals isolated complex [Pd(NO3)4]2− anions, which are surrounded by eight potassium cations and four HNO3 molecules. The complex anions and the cations are associated in layers which are separated by HNO3 molecules. K2[Pd(NO3)4] · 2HNO3 can thus be regarded as a HNO3 intercalation variant of β-K2[Pd(NO3)4]. The characterization is based on single-crystal X-ray and powder X-ray diffraction.

Crystal structure, thermodynamic properties and detonation characterization of bis(5-amino-1,2,4-triazol-3-yl)methane

2020 ◽  
Vol 76 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Hongya Li ◽  
Biao Yan ◽  
Haixia Ma ◽  
Zhiyong Sun ◽  
Yajun Ma ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Detonation Velocity ◽  
Theoretical Calculations ◽  
Detonation Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Equivalent Equation ◽  
Experimental Values ◽  
Experimental Density

Bis(5-amino-1,2,4-triazol-3-yl)methane (BATZM, C5H8N8) was synthesized and its crystal structure characterized by single-crystal X-ray diffraction; it belongs to the space group Fdd2 (orthorhombic) with Z = 8. The structure of BATZM can be described as a V-shaped molecule with reasonable chemical geometry and no disorder. The specific molar heat capacity (Cp,m ) of BATZM was determined using the continuous Cp mode of a microcalorimeter and theoretical calculations, and the Cp,m value is 211.19 J K−1 mol−1 at 298.15 K. The relative deviations between the theoretical and experimental values of Cp,m , HT – H 298.15K and ST – S 298.15K of BATZM are almost equivalent at each temperature. The detonation velocity (D) and detonation pressure (P) of BATZM were estimated using the nitrogen equivalent equation according to the experimental density; BATZM has a higher detonation velocity (7954.87 ± 3.29 m s−1) and detonation pressure (25.72 ± 0.03 GPa) than TNT.

Structural and magnetic characterization of Ho3SbO7 and Dy3SbO7

2001 ◽  
Vol 79 (11-12) ◽  
pp. 1415-1419 ◽  
Author(s):  
T Fennell ◽  
S T Bramwell ◽  
M A Green
Keyword(s):  
Crystal Structure ◽  
Experimental Investigation ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Magnetic Characterization ◽  
X Ray ◽  
Structural And Magnetic Properties ◽  
Ice Model ◽  
Magnetic Rare Earth

We present an experimental investigation of the structural and magnetic properties of Ho3SbO7 and Dy3SbO7. These compounds adopt the Y3TaO7 structure, space group C2221. The magnetic rare-earth ions occupy an intricate lattice related to the pyrochlore lattice that occurs in Ho2Ti2O7 and Dy2Ti2O7. The crystal structure of Ho3SbO7 is determined by Rietveld refinement of the powder X-ray diffraction pattern at ambient temperature, and that of the Dy analogue is inferred to be similar. Magnetic susceptibility measurements show that Ho3SbO7 and Dy3SbO7 have negative Curie–Weiss temperatures: –8.4 K (Ho) and –9.2 K (Dy). Magnetic transitions have been detected at 2.0 K (Ho) and 3.0 K (Dy). We discuss the results in terms of the ``dipolar spin ice model'' that has been used to describe Ho2Ti2O7 and Dy2Ti2O7. PACS Nos.: 75.25+z, 75.50Ee, 61.10Nz

Structural and IR-spectroscopic characterization of magnesium acesulfamate

2016 ◽  
Vol 71 (1) ◽  
pp. 51-55 ◽  
Author(s):  
Oscar E. Piro ◽  
Gustavo A. Echeverría ◽  
Beatriz S. Parajón-Costa ◽  
Enrique J. Baran
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Elemental Analysis ◽  
Spectroscopic Characterization ◽  
Magnesium Carbonate ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Ir Spectroscopic

AbstractMagnesium acesulfamate, Mg(C4H4NO4S)2·6H2O, was prepared by the reaction of acesulfamic acid and magnesium carbonate in aqueous solution, and characterized by elemental analysis. Its crystal structure was determined by single crystal X-ray diffraction methods. The substance crystallizes in the triclinic space group P1̅ with one molecule per unit cell. The FTIR spectrum of the compound was also recorded and is briefly discussed. Some comparisons with other simple acesulfamate and saccharinate salts are also made.

Preparation of KNbO3 Powder by Modified Pechini Method from Layered Perovskite Aqueous Solution

2008 ◽  
Vol 368-372 ◽  
pp. 1883-1885 ◽  
Author(s):  
Takafumi Kokubo ◽  
Kenichi Kakimoto ◽  
Hitoshi Ohsato
Keyword(s):  
Crystal Structure ◽  
Pechini Method ◽  
Layered Perovskite ◽  
Polymeric Precursor Method ◽  
Polymeric Precursor ◽  
Precursor Method ◽  
Thermal Decomposition Behavior ◽  
Modified Pechini Method ◽  
Ft Ir ◽  
Decomposition Behavior

KNbO3 (KN) powder was synthesized by modified Pechini method (polymeric precursor method). KN powder with different crystal structure and grain size distribution was synthesized by different drying temperature. In this paper, the mechanism of preparation of KN powder was discussed in thermal decomposition behavior. The obtained powder was characterized by XRD, TEM, FT-IR and TG-DTA.

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