Structure and temperature-dependent phase transitions of lead-free Bi1/2Na1/2TiO3–Bi1/2K1/2TiO3–K0.5Na0.5NbO3 piezoceramics

2012 ◽  
Vol 27 (19) ◽  
pp. 2466-2478 ◽  
Author(s):  
Eva-Maria Anton ◽  
Ljubomira Ana Schmitt ◽  
Manuel Hinterstein ◽  
Joe Trodahl ◽  
Ben Kowalski ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Lead Free ◽  
Temperature Dependent ◽  
Image Position

Abstract

Temperature and composition dependent phase transitions of lead-free piezoelectric (Bi0.5Na0.5)TiO3–BaTiO3 thin films

2017 ◽  
Vol 19 (30) ◽  
pp. 19992-19997 ◽  
Author(s):  
Zhen Zhou ◽  
Jin Luo ◽  
Wei Sun ◽  
Jing-Feng Li
Keyword(s):  
Thin Films ◽  
Phase Diagram ◽  
Phase Transitions ◽  
Lead Free ◽  
Structure And Properties ◽  
Temperature Dependent

Composition and temperature dependent transitions of structure and properties of BNT–BT films were discussed and a phase diagram was proposed.

On the nature of the phase transitions of aluminosilicate perrhenate sodalite

2020 ◽  
Vol 235 (6-7) ◽  
pp. 213-223
Author(s):  
Hilke Petersen ◽  
Lars Robben ◽  
Thorsten M. Gesing
Keyword(s):  
Raman Spectroscopy ◽  
Phase Transitions ◽  
Decomposition Temperature ◽  
Second Phase ◽  
Structure Property ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Two Phase ◽  
Structure Property Relationships ◽  
Heat Capacity Measurements

AbstractThe temperature-dependent structure-property relationships of the aluminosilicate perrhenate sodalite |Na8(ReO4)2|[AlSiO4]6 (ReO4-SOD) were analysed via powder X-ray diffraction (PXRD), Raman spectroscopy and heat capacity measurements. ReO4-SOD shows two phase transitions in the investigated temperature range (13 K < T < 1480 K). The first one at 218.6(1) K is correlated to the transition of dynamically ordered $P\overline{4}3n$ (> 218.6(1 K) to a statically disordered (<218.6(1) K) SOD template in $P\overline{4}3n$. The loss of the dynamics of the template anion during cooling causes an increase of disorder, indicated by an unusual intensity decrease of the 011-reflection and an increase of the Re-O2 bond length with decreasing temperature. Additionally, Raman spectroscopy shows a distortion of the ReO4 anion. Upon heating the thermal expansion of the sodalite cage originated in the tilt-mechanism causes the second phase transition at 442(1) K resulting in a symmetry-increase from $P\overline{4}3n$ to $Pm\overline{3}n$, the structure with the sodalites full framework expansion. Noteworthy is the high decomposition temperature of 1320(10) K.

Temperature-induced structural phase transitions in RERhSn (RE = Y, Gd-Tm, Lu)

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Simon Engelbert ◽  
Rolf-Dieter Hoffmann ◽  
Jutta Kösters ◽  
Steffen Klenner ◽  
Rainer Pöttgen
Keyword(s):  
Rare Earth ◽  
Phase Transitions ◽  
Driving Force ◽  
Room Temperature ◽  
Structural Phase ◽  
Structural Phase Transitions ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray

Abstract The structures of the equiatomic stannides RERhSn with the smaller rare earth elements Y, Gd-Tm and Lu were reinvestigated on the basis of temperature-dependent single crystal X-ray diffraction data. GdRhSn crystallizes with the aristotype ZrNiAl at 293 and 90 K. For RE = Y, Tb, Ho and Er the HP-CeRuSn type (approximant with space group R3m) is already formed at room temperature, while DyRhSn adopts the HP-CeRuSn type below 280 K. TmRhSn and LuRhSn show incommensurate modulated variants with superspace groups P31m(1/3; 1/3; γ) 000 (No. 157.1.23.1) (γ = 3/8 for TmRhSn and γ = 2/5 for LuRhSn). The driving force for superstructure formation (modulation) is a strengthening of Rh–Sn bonding. The modulation is expressed in a 119Sn Mössbauer spectrum of DyRhSn at 78 K through line broadening.

Temperature dependent fracture toughness of KNN-based lead-free piezoelectric ceramics

2019 ◽  
Vol 174 ◽  
pp. 369-378 ◽  
Author(s):  
Yingwei Li ◽  
Yixuan Liu ◽  
Paul-Erich Öchsner ◽  
Daniel Isaia ◽  
Yichi Zhang ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Piezoelectric Ceramics ◽  
Lead Free ◽  
Temperature Dependent

Dielectric Behavior of Mechano-chemically Synthesized [(CH3NH3)3Bi2Br9]: A Lead Free Hybrid Perovskite

2021 ◽  
Author(s):  
Swagatalaxmi Pujaru ◽  
Priyabrata Sadhukhan ◽  
Basudev Ghosh ◽  
Arup Dhara ◽  
Sachindranath Das
Keyword(s):  
Impedance Spectroscopy ◽  
Complex Impedance ◽  
Negative Temperature ◽  
Dielectric Behavior ◽  
Lead Free ◽  
Published Data ◽  
Temperature Dependent ◽  
Microstructural Parameters ◽  
Hybrid Perovskite ◽  
Refinement Method

Abstract Lead free hybrid halide perovskite (CH3NH3)3Bi2Br9 has been successfully synthesized by mechano-chemical method. The microstructure analysis by Rietveld’s refinement method revealed that the crystal belongs to trigonal system with space group P3 ̅m1. The obtained microstructural parameters are well in agreement with the previously published data. Temperature-dependent ac conductivity, impedance spectroscopy, and complex dielectric properties have been investigated in detail. The negative temperature coefficient of resistance behaviour reveals the semiconducting nature of the materials. The complex impedance spectroscopy also supports the semiconducting nature of the sample with activation energy for conduction ~0.38 eV.

scholarly journals A Theoretical Consideration of the Strength of Snow

1966 ◽  
Vol 6 (43) ◽  
pp. 159-170 ◽  
Author(s):  
G. E. H. Ballard ◽  
E. D. Feldt
Keyword(s):  
Theoretical Consideration ◽  
Failure Surface ◽  
Maximum Strength ◽  
Age Hardening ◽  
Temperature Dependent ◽  
Dependent Parameter ◽  
Potential Failure ◽  
Image Position

AbstractA consideration of possible expressions for the number and size of bonds intersected by a potential failure surface leads to the following expression for the strength of snow, σf, which is age-hardening at a constant porosity n: where σi is the strength of ice, tf is the time at failure, α is a parameter specifically related to the mechanism of bonding, and ω is a temperature-dependent parameter. Allowing tf to become infinite provides the envelope of maximum strength for fully age-hardened snow at any porosity n.

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