scholarly journals High Temperature XRD of Phase Transition in Piezoelectric PbNb2O6 across its Curie Temperature

2016 ◽  
Vol 13 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Udayan De ◽  
Kriti Ranjan Sahu ◽  
Keka R Chakraborty
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Curie Temperature ◽  
Piezoelectric Materials ◽  
Orthorhombic Phase ◽  
X Ray Diffraction ◽  
Lead Metaniobate ◽  
High Temperature Xrd ◽  
Pure Phase ◽  
Xrd Techniques

Orthorhombic phase of lead metaniobate (PbNb2O6) is piezoelectric with a high Curie temperature (>570°C) with high potential of wide use in important high temperature applications that cannot be covered by the popular piezoelectric materials based on BT and PZT. Difficulty of preparing it in pure phase hindered full characterisation and wide use of this long known piezoelectric material. Here,PbNb2O6 pellets have been prepared in pure orthorhombic phase and first characterised by room temperature TEM and XRD techniques, with a satisfying agreement of the two results. Next, we carried out high temperature x-ray diffraction study of its ferroelectric to paraelectric phase transition on heating across the Curie temperature, and also trace the cooling path.On heating the sample to 590°C and cooling back, there is a significant increase of cell volume.

Differential Scanning Calorimetry and Guinier Camera/High-Temperature X-Ray Diffraction Studies of the Oxygen Sublattice Phase Transition in the Yba2Cu3O7−x System

1987 ◽  
Vol 99 ◽  
Author(s):  
David S. Lee ◽  
Zezhong Fu ◽  
Egon Hellstern ◽  
William L. Johnson ◽  
Paul Pietrokowsky ◽  
...  
Keyword(s):  
Phase Transition ◽  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
High Temperature ◽  
Chemical Potential ◽  
X Ray Diffraction ◽  
Oxygen Sublattice ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Xrd Techniques

ABSTRACTWe have studied the phase transition of the oxygen sublattice in the YBa2Cu3O7−x system by Differential Scanning Calorimetry (DSC), Guinier Camera, and high temperature x-ray diffraction (ht-xrd) techniques. The transition was examined under different thermodynamic constraints (constant oxygen partial pressure and constant oxygen concentration) and for a range of oxygen partial pressures. The variation of the endothermic peak temperature with DSC scanning rate was used to deduce an activation energy for the transition. The average activation energy for the process is between 38.7–75.0 kcal/mole(l:2:3) [mole], depending on the thermodynamic constraint imposed on the system.Pressure versus concentration isotherms (P(C)) were used to determine the chemical potential of the oxygen in this system.

In Situ Simultaneous Observation of Phase Transition and Electrical Properties of Pb(Zr,Ti)O3 Thin Film by High Temperature XRD and Electrical Measurement Apparatus

2006 ◽  
Vol 320 ◽  
pp. 53-56 ◽  
Author(s):  
Toru Onoue ◽  
Naoki Wakiya ◽  
Koichi Seo ◽  
Takanori Kiguchi ◽  
Nobuyasu Mizutani ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transition ◽  
High Temperature ◽  
Electrical Measurement ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Temperature Xrd ◽  
Phase Transition Temperatures

Pb(Zr0.05Ti0.95)O3/(La,Sr)CoO3 thin films were prepared by pulsed laser deposition (PLD) on SrTiO3(001) substrates. Phase transition behavior of Pb(Zr0.05Ti0.95)O3 (PZT) was investigated using high temperature X-ray diffraction (HT-XRD) and high-temperature electrical measurement. The phase transition temperature of PZT thin film is larger than bulk one. In 100 and 200nm-thickness epitaxial PZT thin films, the phase transition temperatures obtained from X-ray diffraction measurement and electrical property measurement are in good agreement.

scholarly journals High-temperature phase transition of SrRuO3and SrHfO5: X-ray diffraction and PAC spectroscopy

1996 ◽  
Vol 52 (a1) ◽  
pp. C364-C364
Author(s):  
J. A. Guevara ◽  
S. L. Cuffini ◽  
Y. P. Mascarenhas ◽  
P. de la Presa ◽  
A. Ayala ◽  
...  
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Pac Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Phase Transition

Structural-phase transition in (Cu2Te)2−x(ZnTe)x at high temperature

2021 ◽  
pp. 2150113
Author(s):  
H. B. Gasimov ◽  
R. M. Rzayev
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
High Temperature ◽  
Single Crystals ◽  
Structural Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Xrd Study ◽  
Xrd Method

Cu2Te single crystal was grown by the Bridgman method. X-ray diffraction (XRD) study of Cu2Te single crystals in the temperature range of 293–893 K was performed and possible phase transitions in the mentioned range of temperature have been investigated. (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals also were grown with [Formula: see text], 0.05, 0.10 concentrations and structural properties of the obtained single crystals were investigated by the XRD method in the temperature range 293–893 K. Lattice parameters and possible phase transitions in the mention temperature range were determined for (Cu2Te)[Formula: see text](ZnTe)[Formula: see text] single crystals for [Formula: see text], 0.05, 0.10 concentrations.

Monoclinic-to-orthorhombic phase transition in Cu2(AsO4)(OH) olivenite at high temperature: strain and mode decomposition analyses

2018 ◽  
Vol 82 (2) ◽  
pp. 347-365 ◽  
Author(s):  
Serena C. Tarantino ◽  
Michele Zema ◽  
Athos M. Callegari ◽  
Massimo Boiocchi ◽  
Michael A. Carpenter
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Single Crystal ◽  
Volume Expansion ◽  
Monoclinic Phase ◽  
Orthorhombic Phase ◽  
Unit Cell ◽  
The Other ◽  
Unit Cell Parameters ◽  
Cell Parameters

ABSTRACTA natural olivenite single crystal was submitted to in situ high-temperature single-crystal X-ray diffraction from room temperature (RT) to 500°C. Unit-cell parameters were measured at regular intervals of 25°C, and complete datasets collected at T = 25, 50, 100, 150, 200, 250, 300, 400 and 500°C. Evolution of unit-cell parameters and structure refinements indicates that olivenite undergoes a structural phase transition from P21/n to Pnnm at ~200°C, and eventually becomes isostructural with the other members of the olivenite-mineral group. Volume expansion with temperature is larger in the monoclinic phase – where it follows a non-linear trend – than in the orthorhombic one. Axial and volume expansion coefficients of the orthorhombic olivenite phase are positive and linear and similar to those of the other Cu-bearing member of the mineral family, namely libethenite, but rather different from those of the Zn-analogue arsenate adamite.Distortion of Cu polyhedra is quite high in the olivenite monoclinic phase at RT and goes towards a relative regularization with increasing T until the phase transition occurs. In the orthorhombic phase, no significant variation of the polyhedral distortion parameters is observed with increasing temperature, and maximum expansion is along the b direction and governed by corner-sharing. Landau potential provides a good representation of the macroscopic changes associated with the phase transition, coupling between the strains and the order parameter is responsible for the nearly tricritical character of the transition.

Analysis of phase transition behavior of BaCeO3 with thermal analyses and high temperature X-ray diffraction

2009 ◽  
Vol 180 (17-19) ◽  
pp. 1034-1039 ◽  
Author(s):  
Takeshi Ohzeki ◽  
Shinya Hasegawa ◽  
Misa Shimizu ◽  
Takuya Hashimoto
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Thermal Analyses ◽  
X Ray Diffraction ◽  
Phase Transition Behavior ◽  
X Ray ◽  
Transition Behavior

Phenomena And Mechanism On Phase Transformation Twinning In Nanocrystalline BaTiO3

2010 ◽  
Vol 1256 ◽  
Author(s):  
Sujata Mazumder ◽  
Jiten Ghosh
Keyword(s):  
Phase Transition ◽  
Phase Transformation ◽  
High Temperature ◽  
Intermediate Phase ◽  
High Vacuum ◽  
Point Group ◽  
Atomic Scale ◽  
Twin Structure ◽  
High Temperature Xrd ◽  
Low Symmetry

AbstractThe detailed structure of nanocrystalline BaTiO3 powder during ball milling has been studied using XRD & TEM. The study illustrates important advances in understanding atomic scale properties of this material. Ferroelectric BaTiO3 powder undergoes phase transformation along the sequence Cubic(Pm3m)-tetragonal(P4mm)-orthohombic (Amm2)-rhombohedral(R3m) structure when pressureless sintered samples are cooled from high temperature to low temperature. The high to low symmetry phases are not related to group subgroup symmetry as transformation is discontinuous and first order in nature and the twin relationship in the low symmetry is forbidden by Landau theory. In case of ball milled BaTiO3 powder a continuous and diffusionless phase transition occur via second order to and from a metastable intermediate phase. In this pathway crystallites in the aggregation are twinned and the twin structure is related to crystal point group m3m which in the present case is illustrated as having 6mm symmetry formed under low driving force. The unit cell evolution due to phase transition and the crystallographic relationship are established. The phase transformation, coalescence and twin structure of thermally annealed BaTiO3 nanocrystals under high vacuum has been investigated using in situ high temperature XRD. The structure analysis is performed with the use of the method of computer modelling of disorder structure and simulation of corresponding diffraction pattern.

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