scholarly journals Controlling of Lattice Strains for Crack-Free and Strong Ferroelectric Barium Titanate Films by Post-Thermal Treatment

2021 ◽  
Author(s):  
Bogyu Kim ◽  
Young-Uk Jeon ◽  
Chulwoo Lee ◽  
Hyebi Kim ◽  
Young-Hwan Kim ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Barium Titanate ◽  
Thermal Treatment ◽  
Smooth Surface ◽  
Lattice Strain ◽  
Strain Relaxation ◽  
Lattice Strains ◽  
Post Annealing ◽  
Roughened Surface ◽  
Highly Strained

Abstract In this study, we experimentally demonstrate the fabrication of ultra-smooth and crystalline barium titanate (BTO) films on magnesium oxide (MgO) substrates by engineering the lattice strain and the crystal structure via thermal treatment. We first grow crack-free BTO thin films at oxygen-depleted condition, and enhance the ferroelectric characteristics by post-annealing at high temperature. The roughened surface due to recrystallization during post-annealing is controlled by chemical-mechanical polishing (CMP) to retain the ultra-smooth surface morphology. Oxygen-depleted deposition allows a highly strained BTO film to grow on a MgO substrate with an ultra-smooth surface, and post-annealing relaxes the strain, resulting in the enhancement of the ferroelectricity. From Raman spectroscopy, reciprocal space map (RSM), and capacitance–voltage (C–V) curve measurements, we observe that the ferroelectricity of the BTO film strongly depends on the lattice strain relaxation and the phase transition from a-axis to c-axis oriented crystal structure.

The Microstrain Generation in Cryomilled Nickel by Impurity Nitrogen Atoms

2003 ◽  
Vol 791 ◽  
Author(s):  
Kyung H. Chung ◽  
Enrique J. Lavernia
Keyword(s):  
Crystal Structure ◽  
Octahedral Site ◽  
Strain Field ◽  
Lattice Strain ◽  
The Other ◽  
Single Line ◽  
Impurity Atoms ◽  
Octahedral Sites ◽  
Lattice Strains ◽  
Average Residual

ABSTRACTThe residual microstrains in cryomilled Ni powders, processed under various cryomilling conditions, are measured by XRD and analyzed using a single line approximation (SLA) method. The results show that the average residual microstrains are in the range of 2×10-3 ∼ 6×10-3, and the residual microstrain on the (200) plane is higher than those on the other planes by 33 %. The measured microstrain is proposed to evolve from the introduction of N as impurity atoms in Ni lattice may be attributed to the evolution of the residual microstrain. The N atoms tend to stay in the octahedral sites of Ni, and the diameter of N atom is larger than that of the octahedral site of Ni by 48 %. Accordingly, a lattice strain field is expected around interstitial N atoms that are located at octahedral sites. By comparing the crystal structure around the octahedral site of Ni with that of Ni3N structure, the lattice strains are estimated to be in the range of 5 ∼ 15 %. The results show that the (200) plane has the lattice strains that are two times higher than those in other planes, and this is argued to be the reason for the measured anisotropy of residual microstrain in Ni after cryomilling.

Enhancing static green upconversion luminescence of NaY(MoO4)2: Yb/Er microcrystals via annealing strategy for anti-counterfeiting applications

2021 ◽  
Author(s):  
Xiangyu Zhang ◽  
Jialing Wu ◽  
Peng Wang ◽  
Jie Gao ◽  
Feng Gao ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Thermal Treatment ◽  
Upconversion Luminescence ◽  
Luminescence Enhancement ◽  
Doped Materials

The majority of the fabricated procedures of lanthanide doped materials involve in thermal treatment which often results in crystallite regrowth, stabilizing the specific crystal structure and luminescence enhancement. The efficiency...

scholarly journals Interfacial Structure of Lattice Mismatched bcc(110)/bcc(110) Transition Metal Superlattices

1993 ◽  
Vol 307 ◽  
Author(s):  
Eric E. Fullerton ◽  
S. M. Mini ◽  
A. S. Bommannavar ◽  
C. H. Sowers ◽  
S. N. Ehrlich ◽  
...  
Keyword(s):  
Lattice Strain ◽  
Structural Model ◽  
Interfacial Structure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lattice Strains ◽  
The Individual ◽  
Structural Characterizations ◽  
Modulation Wavelength ◽  
Coherent Interfaces

ABSTRACTWe present structural characterizations of a series of sputtered Fe/Nb and V/Nb superlattices by high-angle x-ray diffraction. Diffraction scans were performed with the scattering vector at various angles (χ) with respect to the layers. χ=0° diffraction spectra (normal to the layers) were fitted to a general structural model to determine the (110) lattice strains, interfacial disorder and interdiffusion. χ>0° spectra probe the lattice strain of the individual layers and the in-plane interfacial coherence. Both systems form incoherent interfaces above a critical modulation wavelength (ΛC). At ΛC, the Fe/Nb system undergoes a crystalline-to-amorphous transition while the V/Nb forms in-plane coherent interfaces.

Properties of Barium Titanate in Connection with Its Crystal Structure

Science ◽  
1949 ◽  
Vol 109 (2843) ◽  
pp. 632-635 ◽  
Author(s):  
G. H. Jonker ◽  
J. H. van Santen
Keyword(s):  
Crystal Structure ◽  
Barium Titanate

An investigation of the polytypical structure of Sr0.2Ba0.8CoO3–δ by neutron powder diffraction

2010 ◽  
Vol 225 (5) ◽  
Author(s):  
Cristina de la Calle ◽  
José Antonio Alonso ◽  
Ainara Aguadero ◽  
Maria Teresa Fernández-Díaz ◽  
Florence Porcher
Keyword(s):  
Crystal Structure ◽  
Thermal Treatment ◽  
Powder Diffraction ◽  
Oxygen Pressure ◽  
Room Temperature ◽  
Neutron Powder Diffraction ◽  
Slow Cooling ◽  
High Oxygen Pressure ◽  
Citrate Precursor

AbstractThe preparation and characterization of two polymorphs of the title composition are described. One hexagonal perovskite, labeled as “H”, was synthesized by thermal treatment of reactive citrate precursor at 900 °C in high oxygen pressure (20 MPa) followed by slow cooling (10 °C/min) to room temperature. This 1D-structure displays aThe evolution of the crystal structure of the 3C phase has been explored

scholarly journals Intramolecular photocycloaddition of 3-substituted dithiosuccinimides: Facile synthesis and the crystal structure of highly strained multicyclic fused thietane system.

1986 ◽  
Vol 34 (3) ◽  
pp. 1411-1414 ◽  
Author(s):  
Kazuaki Oda ◽  
Minoru Machida ◽  
Keiichi Aoe ◽  
Yoshihiko Nishibata ◽  
Yasuhiko Sato ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Facile Synthesis ◽  
Highly Strained

A re-examination of the relationship between lattice strain, octahedral tilt angle and octahedral strain in rhombohedral perovskites

1996 ◽  
Vol 52 (6) ◽  
pp. 954-960 ◽  
Author(s):  
N. W. Thomas
Keyword(s):  
Tilt Angle ◽  
Lattice Strain ◽  
Numerical Solutions ◽  
Volume Ratio ◽  
Group Symmetry ◽  
Acta Cryst ◽  
Fourth Degree ◽  
Parametric Curves ◽  
Lattice Strains ◽  
The Relationship

A new expression is proposed for the relationship between lattice strain 90°− αpc ( αpc: pseudo-cubic angle) and mean BO6 octahedral tilt angle <ω> in rhombohedral perovskites ABO3. It is derived from volumetric arguments, leading to a cubic equation which incorporates lattice strain 90° −αpc and octahedral elongation explicitly. Numerical solutions of this equation are derived for equally spaced values of octahedral strain, giving rise to a set of parametric curves which relate ω to 90° − αpc for different values of η. These curves can be represented as polynomials of the fourth degree, thereby enabling their routine use in the analysis of rhombohedral perovskite structures. It is anticipated that these parametric curves will supersede earlier work [Megaw & Darlington (1975). Acta Cryst. A31, 161–173], in which an analytical expression was derived linking 90° − αpc, ω and octahedral strain for positive lattice strains only. By comparison, the relationship proposed here accommodates both negative and positive lattice strains. Correlations between values of <ω>, η, 90° − αpc and space-group symmetry are found, with an analysis of known rhombohedral and orthorhombic Pnma structures revealing the importance of cationic charges in determining symmetry. Since the polyhedral volume ratio VA/VB may be quantitatively related to <ω>, allowed values of tilt angle, lattice strain and octahedral elongation may be inferred for a given composition, which has characteristic values of VA and VB .

Crystal structure of δ-isobutoxypentabromo-cyclododecanes, kinetics and selectivity of their isomerization during thermal treatment of flame-proofed polystyrenes

Chemosphere ◽  
2011 ◽  
Vol 83 (11) ◽  
pp. 1568-1574 ◽  
Author(s):  
Norbert V. Heeb ◽  
Heidi Graf ◽  
W. Bernd Schweizer ◽  
Meret Heeb ◽  
P. Lienemann
Keyword(s):  
Crystal Structure ◽  
Thermal Treatment

Lattice Strain Pole Figures Analysis in Titanium during Uniaxial Deformation

2017 ◽  
Vol 905 ◽  
pp. 74-80
Author(s):  
David Gloaguen ◽  
Baptiste Girault ◽  
Jamal Fajoui ◽  
Vincent Klosek ◽  
Marie José Moya
Keyword(s):  
Experimental Data ◽  
Neutron Diffraction ◽  
Lattice Strain ◽  
Pure Titanium ◽  
Tensile Load ◽  
Uniaxial Tensile ◽  
Lattice Strains ◽  
Pole Figures ◽  
In Situ Neutron Diffraction

A theoretical and experimental study was carry out to investigate deformation mechanisms in a textured titanium alloy. In situ neutron diffraction measurements were performed to analyze different {hk.l} family planes ({10.0}, {10.1}, {11.0} and {00.2}) and determine the corresponding internal strain pole figures. This method was applied to a pure titanium (a-Ti) submitted to a uniaxial tensile load up to 2 %. The experimental data was then used to validate the EPSC model in order to predict the distribution of lattice strains determined by neutron diffraction for various diffraction vector directions. This comparison reveals that the model results were in good agreement with the experimental data and the simulations reproduced the lattice strain development observed on the strain pole figures determined by neutron diffraction.

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