Increased cubic–tetragonal phase transition temperature and resistivity hysteresis of surface vacuum annealed SrTiO3

2011 ◽  
Vol 105 (1) ◽  
pp. 103-109 ◽  
Author(s):  
Tina Nestler ◽  
Kay Potzger ◽  
Hartmut Stöcker ◽  
Barbara Abendroth ◽  
Ralph Strohmeyer ◽  
...  
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Tetragonal Phase ◽  
Tetragonal Phase Transition

Thermodynamic analyses of the orthorhombic-to-tetragonal phase transition in Pr2−xNdxNiO4+δ under controlled oxygen partial pressures

2020 ◽  
Vol 49 (34) ◽  
pp. 11931-11941
Author(s):  
Eiki Niwa ◽  
Tsubasa Sato ◽  
Takuya Hashimoto
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Tetragonal Phase ◽  
Structural Phase ◽  
Entropy Change ◽  
Enthalpy Change ◽  
Standard Entropy ◽  
Partial Pressures ◽  
Tetragonal Phase Transition

The standard entropy change, ΔS°, and enthalpy change, ΔH°, at the structural phase transition of Pr2−xNdxNiO4+δ and their impact on variation of phase transition temperature by Nd content.

scholarly journals The growth status of relaxor-based ferroelectric crystals and their development trends

2014 ◽  
Vol 04 (01) ◽  
pp. 1450002
Author(s):  
Guisheng Xu ◽  
Danfeng Yang ◽  
Jinfeng Liu ◽  
Ying Liu ◽  
Xiaxia Chen
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Phase Transition Temperature ◽  
Tetragonal Phase ◽  
Coercive Field ◽  
Growth Efficiency ◽  
Mechanical Quality Factor ◽  
Development Trends ◽  
Ferroelectric Crystals ◽  
Tetragonal Phase Transition

Our progress in the growth of ternary system Pb ( In 1/2 Nb 1/2) O 3– Pb ( Mg 1/3 Nb 2/3) O 3– PbTiO 3 (PIMNT) crystals and reviews on the possible developing trends in the piezoelectric crystals are presented. Large PIMNT crystals with 3 inches in diameter have been grown by using a modified Bridgman method. Meanwhile, Mn -doped PIMNT crystals have also been obtained. PIMNT crystals exhibit Curie temperature Tc ~ 190° C , rhombohedral–tetragonal phase transition temperature T rt > 100° C and coercive field Ec ~ 5.0–7.0 kV/cm on (001) cuts. Meanwhile, higher piezoelectric constant d32 ~ -1500–2200 pC/N , d15 ~ 4000–6000 pC/N and coercive field Ec ~ 7.0–9.0 kV/cm have been achieved on (110) cuts. The development trends of relaxor-based ferroelectric crystals are suggested to grow novel crystals with high rhombohedral–tetragonal phase transition temperature T rt > 150 ~ 160° C and/or high coercive field Ec and mechanical quality factor Qm, to promote growth efficiency of PIMNT crystals and to create new growth methods fitting for the growth of metastable or instable crystals.

Temperature-dependent photoluminescence properties of mixed-cation methylammonium–formamidium lead iodide [HC(NH2)2]x[CH3NH3]1−xPbI3 perovskite nanostructures

2017 ◽  
Vol 5 (46) ◽  
pp. 12057-12061 ◽  
Author(s):  
Hongge Zheng ◽  
Jun Dai ◽  
Junjie Duan ◽  
Feng Chen ◽  
Gangyi Zhu ◽  
...  
Keyword(s):  
Phase Transition ◽  
Optical Properties ◽  
Transition Temperature ◽  
Tetragonal Phase ◽  
Photoluminescence Properties ◽  
Lead Iodide ◽  
Temperature Dependent ◽  
Urbach Tail ◽  
Tetragonal Phase Transition ◽  
Temperature Dependent Photoluminescence

Orthorhombic–tetragonal phase transition, temperature-dependent PL related optical properties and Urbach tail characteristics are systematically investigated in the FAxMA1−xPbI3 nanostructures.

scholarly journals Phase transition and dielectric properties of BaTiO3 ceramics containing 10 mol% BaGeO3

2018 ◽  
Author(s):  
Roberto Köferstein
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Phase Transition Temperature ◽  
Ferroelectric Phase ◽  
Grain Sizes ◽  
Ferroelectric Phase Transition Temperature ◽  
Permittivity Maximum ◽  
Tetragonal Phase Transition ◽  
Maximum Permittivity

Dielectric properties and the cubic ? tetragonal phase transition temperature ofdense BaTiO3 ceramics containing 10 mol% BaGeO3, sintered between 840 and 1350 °C,have been investigated. The ceramic bodies were prepared from a nano-sized BaTi0.9/Ge0.1O3powder consisting of both BaTiO3 and BaGeO3 phases. The addition of BaGeO3 leads to areduction and broadening of the permittivity maximum, and to a small downshift of theparaelectric ? ferroelectric phase transition temperature, compared to a pure BaTiO3 ceramic.Lower sintering temperatures and thus small grain sizes of the ceramics cause an additionalreduction of the maximum permittivity down to 2800. Both DTA and dilatometricmeasurements reveal also a downshifting of the phase transition temperature, as well as adecrease of the latent heat.

The structure of membranes and membrane proteins embedded in amorphous ice

1992 ◽  
Vol 50 (1) ◽  
pp. 432-433
Author(s):  
Uwe Lücken ◽  
Joachim Jäger
Keyword(s):  
Phase Transition ◽  
Transition Temperature ◽  
Membrane Proteins ◽  
Phase Transition Temperature ◽  
Lipid Vesicles ◽  
Freezing Stress ◽  
Amorphous Ice ◽  
Different Temperatures ◽  
Band Pass ◽  
Lipid Polymorphism

TEM imaging of frozen-hydrated lipid vesicles has been done by several groups Thermotrophic and lyotrophic polymorphism has been reported. By using image processing, computer simulation and tilt experiments, we tried to learn about the influence of freezing-stress and defocus artifacts on the lipid polymorphism and fine structure of the bilayer profile. We show integrated membrane proteins do modulate the bilayer structure and the morphology of the vesicles.Phase transitions of DMPC vesicles were visualized after freezing under equilibrium conditions at different temperatures in a controlled-environment vitrification system. Below the main phase transition temperature of 24°C (Fig. 1), vesicles show a facetted appearance due to the quasicrystalline areas. A gradual increase in temperature leads to melting processes with different morphology in the bilayer profile. Far above the phase transition temperature the bilayer profile is still present. In the band-pass-filtered images (Fig. 2) no significant change in the width of the bilayer profile is visible.

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