EFFECT OF Nb2O5 ON THE ELASTIC BEHAVIOR OF PZT FERROELECTRIC MATERIALS

2002 ◽  
Vol 16 (03) ◽  
pp. 79-85
Author(s):  
Y. PURUSHOTHAM ◽  
O. P. THAKUR ◽  
CHANDRA PRAKASH ◽  
P. VENUGOPAL REDDY
Keyword(s):  
Elastic Moduli ◽  
Solid State Reaction Method ◽  
Ferroelectric Materials ◽  
Ferroelectric Ceramics ◽  
Elastic Behavior ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Pulse Transmission

A series of ferroelectric ceramics with the compositional formula PbZr0.52Ti0.48O3 + x wt% of Nb2O5 were prepared by the solid state reaction method. Samples were characterized by studying their X-ray diffraction and dielectric measurements. The longitudinal and shear wave velocities and corresponding elastic moduli were determined at room temperature by using the pulse transmission technique. The values of Young's modulus (E), and the rigidity (n) and bulk (k) moduli were corrected to theoretical density and were found to increase with increasing dopant concentration. The variation of elastic moduli and other elastic parameters such as Debye temperature (θ D ) with composition are explained qualitatively.

ELASTIC BEHAVIOR OF SOME SUBSTITUTED Sr–Zn W-TYPE HEXAGONAL FERRITES

1999 ◽  
Vol 13 (27) ◽  
pp. 991-998 ◽  
Author(s):  
Y. PURUSHOTHAM ◽  
P. VENUGOPAL REDDY
Keyword(s):  
Linear Relationship ◽  
Room Temperature ◽  
Elastic Moduli ◽  
Dopant Concentration ◽  
Elastic Behavior ◽  
Hexagonal Ferrites ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Pulse Transmission ◽  
Transmission Technique

In the present work, we investigate the elastic behavior of monovalent and divalent doped Sr–Zn W-type hexagonal ferrites at room temperature by measuring their longitudinal and shear wave velocities using a pulse transmission technique. The values of Young (E) and rigidity (G) moduli have been corrected to the theoretical density. The zero porosity values of both the elastic moduli are found to increase with increasing dopant concentration. Further, a linear relationship between the Debye temperature and the average sound velocity has also been observed and the behavior is explained qualitatively.

ELASTIC BEHAVIOR OF GERMANIUM-SUBSTITUTED LITHIUM FERRITES

1995 ◽  
Vol 09 (01) ◽  
pp. 39-44 ◽  
Author(s):  
Y. PURUSHOTHAM ◽  
P. VENUGOPAL REDDY ◽  
PRAN KISHAN ◽  
NITENDAR KUMAR
Keyword(s):  
Room Temperature ◽  
Elastic Moduli ◽  
Elastic Behavior ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Pulse Transmission ◽  
Power Equation ◽  
Lithium Ferrites ◽  
Transmission Technique ◽  
Germanium Concentration

The longitudinal and shear wave velocities of germanium-substituted lithium ferrites were determined at room temperature by the pulse transmission technique. Young's (E) and rigidity (n) moduli have been corrected to theoretical density by a power equation. The zero porous corrected values of both the elastic moduli (Young's and rigidity) are found to increase with increasing germanium concentration. A linear relationship between the Debye temperature and the average sound velocity has also been observed.

Dielectric Properties and Raman Spectroscopy in Ca-Substituted Na0.5Bi0.5TiO3 Ferroelectric Ceramics

2011 ◽  
Vol 324 ◽  
pp. 298-301 ◽  
Author(s):  
Roy Jean Roukos ◽  
Olivier Bidault ◽  
Julien Pansiot ◽  
Ludivine Minier ◽  
Lucien Saviot
Keyword(s):  
Raman Spectroscopy ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Rhombohedral Phase ◽  
Xrd Analysis ◽  
Solid State Reaction Method ◽  
Ferroelectric Ceramics ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
X Ray

Lead free Na0.5Bi0.5TiO3 (NBT) and (Na0.5Bi0.5TiO3)1-x(CaTiO3)x (NBT-CT) piezoelectric ceramics with the perovskite structure were studied. The NBT and NBT-CT samples were synthesized using a solid-state reaction method and characterized with X-ray diffraction (XRD), Raman spectroscopy and dielectric measurements for several compositions (x = 0, 0.07, 0.15) at room temperature. The XRD analysis showed a stabilization of a rhombohedral phase at a low concentration of Ca (0 < x <0.15), whereas Raman spectra reveal a strong modification for the sample with x = 0.15. The dielectric properties of these ceramics were studied by measuring impedance in the 79-451K temperature range for unpoled and field cooling with an electric field (FC) conditions.

ELASTIC BEHAVIOR OF Pr SUBSTITUTED Y-123 SUPERCONDUCTING MATERIALS

2006 ◽  
Vol 20 (14) ◽  
pp. 843-847 ◽  
Author(s):  
B. N. DOLE ◽  
Y. PURUSHOTHAM ◽  
P. VENUGOPAL REDDY ◽  
S. S. SHAH
Keyword(s):  
High Temperature ◽  
Linear Relationship ◽  
Sound Velocity ◽  
Room Temperature ◽  
Elastic Moduli ◽  
High Temperature Superconductors ◽  
Elastic Behavior ◽  
Wave Velocities ◽  
Pulse Transmission ◽  
Transmission Technique

The longitudinal (Vl) and shear (Vs) wave velocities of Praseodymium substituted YB 2 Cu 3 O 7-δ high temperature superconductors were determined at room temperature by the pulse transmission technique. The values of Young's (E), rigidity (n) and bulk (k) moduli have been corrected to zero porosity. The zero porous corrected values of the elastic moduli are found to increase with increasing Praseodymium concentration. A linear relationship between the Debye temperature (θD) and average sound velocity (Vm) has also been observed and the behavior is explained qualitatively.

Structural and Dielectric Properties of Na0.5Bi0.5TiO3 Ferroelectric Ceramics

2012 ◽  
Vol 585 ◽  
pp. 219-223
Author(s):  
Rekha Kumari ◽  
N. Ahlawat ◽  
Ashish Agarwal ◽  
M. Sindhu ◽  
N.N. Ahlawat
Keyword(s):  
Dielectric Properties ◽  
Solid State Reaction Method ◽  
Wide Frequency Range ◽  
Ferroelectric Ceramics ◽  
Frequency Range ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Reaction Method ◽  
X Ray ◽  
Different Temperatures

Na0.5Bi0.5TiO3 (NBT) ceramics were synthesized by conventional solid state reaction method. Structural and dielectric properties of these ceramics were investigated. Crystalline phase of sintered ceramics was investigated by X-ray diffraction (XRD). The Rietveld refinement of powder X-ray diffraction revealed that the prepared ceramics exhibit the rhombohedral space group R3c. Dielectric properties of Na0.5Bi0. analyzer.5TiO3 (NBT) ceramics were studied at different temperatures in a wide frequency range using impedance

Elastic Behavior of YMnO3 and ErMnO3 Manganites

2003 ◽  
Vol 17 (20n21) ◽  
pp. 1119-1125 ◽  
Author(s):  
M. Chandra Sekhar ◽  
K. Padmavathi ◽  
J. G. Park ◽  
P. Venugopal Reddy
Keyword(s):  
Room Temperature ◽  
Elastic Moduli ◽  
Solid State Reaction Method ◽  
Elastic Behavior ◽  
Velocity Measurements ◽  
Qualitative Explanation ◽  
Reaction Method ◽  
X Ray ◽  
Young’S Moduli ◽  
Ray Density

The manganite oxides, YMnO 3 and ErMnO 3 having hexagonal structures were prepared by the solid state reaction method. After characterizing these materials by studying their various physical properties such as lattice parameters, X-ray density, bulk density etc., ultrasonic velocity measurements were carried out over a temperature range 80–300 K to investigate their elastic behavior. As the materials are porous, the measured elastic moduli were corrected to zero porosity. Using the room temperature elastic moduli, Debye temperature values of both the manganites have also been obtained. Surprisingly it has been found that the Young's moduli of both the materials increase continuously with decreasing temperature. A qualitative explanation for the observed behavior is offered.

scholarly journals Composition dependence of dielectric properties in Pb(Zn1∕3Nb2∕3)O3–PbTiO3–BaTiO3 (PZN–PT–BT) relaxor ferroelectric ceramics

2017 ◽  
Vol 07 (02) ◽  
pp. 1750008
Author(s):  
Qiang Gao ◽  
Li Jin ◽  
Yu Cui ◽  
Ye Zhao ◽  
Kun Yu ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Composition Dependence ◽  
Solid State Reaction Method ◽  
Ferroelectric Ceramics ◽  
Dielectric Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cation Disorder ◽  
Diffusion Phase ◽  
A Site

Perovskite solid solution ceramics of PZN–PT–BT with several compositions were synthesized by solid-state reaction method. X-ray diffraction results indicate pure perovskite structures for all samples. Dielectric measurements show that the implicit Ba(Zn[Formula: see text]Nb[Formula: see text])O3(BZN) composition could broaden the diffusion phase transition (DPT) peaks and lower the [Formula: see text] and [Formula: see text] values. The observed dielectric properties may be caused by the increased cation disorder due to the substitution of barium onto the A-site and titanium onto the B-site.

scholarly journals Lattice strain during compressive loading of AlCrFeNiTi multi-principal element alloys

2021 ◽  
Author(s):  
M. Reiberg ◽  
X. Li ◽  
E. Maawad ◽  
E. Werner
Keyword(s):  
Room Temperature ◽  
Elastic Moduli ◽  
Electron Backscatter Diffraction ◽  
Elastic Behavior ◽  
Body Centered Cubic ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
Principal Element ◽  
X Ray ◽  
Full Heusler

AbstractIn this work, multi-principal element alloys (MPEAs) with the five base elements Al, Cr, Fe, Ni and Ti plus elements in minor amounts were produced by powder metallurgy and their microstructure and elastic behavior were analyzed via light and scanning electron microscopy, electron backscatter diffraction (EBSD) and synchrotron X-ray diffraction. The two studied compositions are an MPEA with Al, Cr, Fe, Ni and Ti in equimolar ratio as well as a similar composition with a concentration of Ti reduced to 10 mol%. The goal is to analyze the microstructural behavior of these compositions during macroscopic loading in dependence of chemical composition and phases present. Analysis via synchrotron X-ray diffraction predicts the presence of body-centered cubic phases, Full Heusler-phases and C14_Laves-phases in both compositions, MPEA5 and MPEA_Ti10. Synchrotron X-ray diffraction offers the possibility to monitor the deformation of these phases during macroscopic loading of specimens. Thermodynamic calculations of stable phases predicted a microstructure of MPEA5 consisting of body-centered cubic and Full Heusler-phases at room temperature. Further calculation and X-ray diffraction experiments showed the stabilization of minor amounts of C14_Laves-phase ($$\hbox {Fe}_2\hbox {Ti}$$ Fe 2 Ti ) at room temperature with a decreasing amount of Ti. MPEA5 showed the development of long and un-branched cracks during compressive testing, which resulted in a remarkable decrease in lattice-dependent elastic moduli. MPEA_Ti10 exhibited branched cracks during compression tests. Also, the lattice-dependent elastic moduli of MPEA_Ti10 did not change notably during the compression tests. In both compositions, the Full Heusler-phase showed the lowest lattice-dependent elastic moduli, hence taking the largest share of the overall deformation among all phases present in the materials under macroscopic loading.

ELASTICITY STUDIES OF SOME Bi-Pb-Sr-Ca-Cu-O HIGH-Tc SUPERCONDUCTING MATERIALS

1993 ◽  
Vol 07 (13n14) ◽  
pp. 935-947 ◽  
Author(s):  
S. SHEKAR ◽  
P. VENUGOPAL REDDY
Keyword(s):  
Lead Concentration ◽  
Solid State Reaction Method ◽  
High Tc ◽  
Wave Velocities ◽  
Shear Wave Velocities ◽  
Pulse Transmission ◽  
Conducting Materials ◽  
Rigidity Modulus ◽  
Super Conducting ◽  
Binding Forces

Longitudinal and shear wave velocities of lead-substituted Bi-Sr-Ca-Cu-O (2223) super-conducting materials prepared by the three-step matrix solid state reaction method have been measured by the pulse transmission technique. Using the data, several elasticity parameters like Young’s modulus, rigidity modulus, Poisson’s ratio, Debye temperature, etc. have been evaluated. Variation of elasticity parameters with lead concentration has been explained in terms of binding forces between various atoms. It has been observed that these materials are behaving like any other oxide materials.

Electron Microscope study of commensurate-incommensurate phase transition in BaZnGeO4

1990 ◽  
Vol 48 (4) ◽  
pp. 172-173
Author(s):  
Naoki Yamamoto ◽  
Makoto Kikuchi ◽  
Tooru Atake ◽  
Akihiro Hamano ◽  
Yasutoshi Saito
Keyword(s):  
Phase Transition ◽  
Electron Microscope Study ◽  
Room Temperature ◽  
Hexagonal Lattice ◽  
Ferroelectric Materials ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Periodic Arrays ◽  
Modulation Wave Vector

BaZnGeO4 undergoes many phase transitions from I to V phase. The highest temperature phase I has a BaAl2O4 type structure with a hexagonal lattice. Recent X-ray diffraction study showed that the incommensurate (IC) lattice modulation appears along the c axis in the III and IV phases with a period of about 4c, and a commensurate (C) phase with a modulated period of 4c exists between the III and IV phases in the narrow temperature region (—58°C to —47°C on cooling), called the III' phase. The modulations in the IC phases are considered displacive type, but the detailed structures have not been studied. It is also not clear whether the modulation changes into periodic arrays of discommensurations (DC’s) near the III-III' and IV-V phase transition temperature as found in the ferroelectric materials such as Rb2ZnCl4.At room temperature (III phase) satellite reflections were seen around the fundamental reflections in a diffraction pattern (Fig.1) and they aligned along a certain direction deviated from the c* direction, which indicates that the modulation wave vector q tilts from the c* axis. The tilt angle is about 2 degree at room temperature and depends on temperature.

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