Hypersonic and Dielectric Studies of Relaxor Ferroelectric Single Crystal

1999 ◽  
Vol 604 ◽  
Author(s):  
Chi-Shun Tu ◽  
V.H. Schmiidt ◽  
C.-H. Yeh ◽  
L.-F. Chen ◽  
C.-L. Tsai
Keyword(s):  
Phase Transition ◽  
Dielectric Permittivity ◽  
Single Crystal ◽  
Thermal Hysteresis ◽  
Relaxor Ferroelectric ◽  
Dipolar Relaxation ◽  
First Order ◽  
Dielectric Data ◽  
Scattering Spectra ◽  
Ferroelectric Single Crystal

AbstractBoth the longitudinal (LA) Brillouin back-scattering spectra and dielectric permittivity along the [001] direction have been measured as a function of temperature for a relaxor ferroelectric single crystal (PbMg1/3Nb2/3O3)0.68(PbTiO3)0.32 (PMN-32%PT). A sharp ferroelectric phase transition (which is associated with a Landau-Khalatnikov-like phonon damping maximum) was observed near 445 K. As temperature increases, a diffuse phase transition was detected near 280 K. In addition, the nature of the thermal hysteresis for the dielectric permittivity confirms that these transitions (near 280 and 445 K for heating procedure) are diffuse first-order and first-order, It respectively. The dielectric data prove the existence of an electric dipolar relaxation process below 300 K.

Verification of first‐order magnetic phase transition in single crystal iron films

1982 ◽  
Vol 53 (11) ◽  
pp. 7966-7968 ◽  
Author(s):  
F. J. Rachford ◽  
G. A. Prinz ◽  
J. J. Krebs ◽  
K. B. Hathaway
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Magnetic Phase Transition ◽  
Magnetic Phase ◽  
Iron Films ◽  
First Order ◽  
Order Magnetic Phase Transition

Reversible crystal deformation of a single-crystal host of copper(ii) 1-naphthoate—pyrazine through crystal phase transition induced by methanol vapor sorption

2015 ◽  
Vol 51 (24) ◽  
pp. 5024-5027 ◽  
Author(s):  
Yuichi Takasaki ◽  
Satoshi Takamizawa
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Order Phase Transition ◽  
Crystal Phase ◽  
Vapor Sorption ◽  
Methanol Vapor ◽  
First Order ◽  
First Order Phase Transition ◽  
Crystal Phase Transition ◽  
First Order Phase

A single-crystal host of copper(ii) 1-naphthoate—pyrazine reversibly deformed during the first-order phase transition induced by methanol vapor desorption and adsorption.

Electrical Properties of Pb(Mg1/3Nb2/3)-PbTiO3 Ferroelectric Single Crystal

2009 ◽  
Vol 421-422 ◽  
pp. 419-422
Author(s):  
Ghulam Shabbir ◽  
Seiji Kojima
Keyword(s):  
Phase Transition ◽  
Electrical Properties ◽  
Single Crystal ◽  
Ferroelectric Phase Transition ◽  
Ferroelectric Phase ◽  
Charge Carriers ◽  
Frequency Range ◽  
Thermally Activated ◽  
Phase Transition Temperatures ◽  
Ferroelectric Single Crystal

The electrical properties of [001]-oriented morphotropic phase boundary (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-33%PT) single crystal have investigated as a function of temperature and frequency. The ac-conductivity exhibited continuous dispersion at all temperatures and frequency range examined and was associated to the thermally activated space charge carriers and local off-centering of Ti4+ and Pb2+ ions. The variations in ferroelectric phase transition temperatures observed in the poled state were associated to the polarization fluctuations and phase co-existence.

A temperature-induced order–disorder phase transition in a 4-substituted 4,2′:6′,4′′-terpyridine

2015 ◽  
Vol 71 (6) ◽  
pp. 805-813 ◽  
Author(s):  
Juan Granifo ◽  
Marleen Westermeyer ◽  
Maricel Riquelme ◽  
Rubén Gaviño ◽  
Sebastián Suárez ◽  
...  
Keyword(s):  
Phase Transition ◽  
Single Crystal ◽  
Single Molecule ◽  
Temperature Phase ◽  
Asymmetric Unit ◽  
Phase Form ◽  
Space Group ◽  
Cell Parameters ◽  
Disorder Phase Transition ◽  
First Order

Crystals of 4′-(isoquinolin-4-yl)-4,2′:6′,4′′-terpyridine (iqtp), C24H16N4, grown from an ethanol solution, undergo a reversible first-order single-crystal to single-crystal phase transition at T c in the range 273–275 K, from a disordered higher-temperature phase [form (I)] in the space group P21/c, with one single molecule in the asymmetric unit, to an ordered lower-temperature one [form (II)] in the space group P21/n, with two independent molecules in the asymmetric unit. There is a group–subgroup relationship linking (I)–(II), due to cell doubling and the disappearance of a number of symmetry operations. In addition to X-ray diffraction, the transition has been monitored by Raman spectroscopy and differential scanning calorimetry, the latter disclosing an enthalpy change of 0.72 (6) kJ mol−1. Variations of the unit-cell parameters with temperature between 170 and 293 K are presented. The evolution of diffraction spots in the vicinity of the transition temperature shows the coexistence of both phases, confirming the first-order character of the transition. Structural details of both phases are analyzed and intermolecular interactions compared in order to investigate the mechanism of the phase transition. A three-dimensional Hirshfeld surface analysis was performed to corroborate the significant changes in the intermolecular features.

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