A simplified model for the phase composition curve of saline soils considering the second phase transition

2020 ◽  
Author(s):  
Liyang Wang ◽  
Jiankun Liu ◽  
Xinbao Yu ◽  
Tengfei Wang ◽  
Ruiling Feng
Keyword(s):  
Phase Transition ◽  
Phase Composition ◽  
Simplified Model ◽  
Saline Soils ◽  
Second Phase ◽  
Composition Curve

Sb5+ Modified Phase Transition in (Li, Na, K)(Nb1-xSbx)O3 Piezoelectric Ceramics

2016 ◽  
Vol 848 ◽  
pp. 339-343
Author(s):  
Xiao Kun Zhao ◽  
Bo Ping Zhang ◽  
Lei Zhao ◽  
Li Feng Zhu
Keyword(s):  
Phase Transition ◽  
Phase Boundary ◽  
Coupling Coefficient ◽  
Electromechanical Coupling ◽  
Piezoelectric Coefficient ◽  
Electromechanical Coupling Coefficient ◽  
Second Phase ◽  
Phase Transition Temperatures ◽  
Two Peaks ◽  
Planar Mode

The modified behavior of the phase transition temperatures (TO-T and/or TC) between orthorhombic (O), tetragonal (T) and cubic (C) that caused by doping Sb5+ in (Li0.052Na0.493K0.455)(Nb1-xSbx)O3 (LNKNSx) ceramics was reported in the present investigation. The results show that differing from the insensitive TO-T to the Sb5+ content, TC splits into two peaks TCI and TCII when doping Sb5+. The decreased TCI by raising x may be ascribed to the Sb-rich grains and the settled TCII round 480 °C resulting from the Sb-lack ones. The enhanced piezoelectric coefficient d33 value of 263 pC/N and planar mode electromechanical coupling coefficient kp value of 42.5% at x=0.052 can be attributed to the polymorphic phase boundary (PPB) behavior with an appropriate ratio between T and O phases without any second phase.

Particle anisotropy and crystalline phase transition in one-pot synthesis of nano-zirconia: a causal relationship

CrystEngComm ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 879-888 ◽  
Author(s):  
Francesca Tana ◽  
Andrea Serafini ◽  
Luca Lutterotti ◽  
Alberto Cigada ◽  
Fabio Variola ◽  
...  
Keyword(s):  
Phase Transition ◽  
Phase Composition ◽  
Causal Relationship ◽  
Crystalline Phase ◽  
One Pot ◽  
One Pot Synthesis ◽  
Nanocrystal Growth ◽  
Particle Anisotropy ◽  
Morphological Transformations ◽  
Crystalline Phase Transition

The effects of experimental variables on zirconia nanocrystal growth are investigated, correlating the morphological transformations with phase composition in synthesized nanopowders.

X-ray diffraction and Raman study of DL-alanine at high pressure: revision of phase transitions

2012 ◽  
Vol 68 (4) ◽  
pp. 412-423 ◽  
Author(s):  
Nikolay A. Tumanov ◽  
Elena V. Boldyreva
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Structural Phase ◽  
Group Symmetry ◽  
Second Phase ◽  
Structural Phase Transitions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Raman Study

The effect of pressure on DL-alanine has been studied by X-ray powder diffraction (up to 8.3 GPa), single-crystal X-ray diffraction and Raman spectroscopy (up to ∼ 6 GPa). No structural phase transitions have been observed. At ∼ 1.5–2 GPa, cell parameters b and c become accidentally equal to each other, but the space-group symmetry does not change. There is no phase transition between 1.7 and 2.3 GPa, contrary to what has been reported earlier [Belo et al. (2010). Vibr. Spectrosc. 54, 107–111]. The presence of the second phase transition, which was claimed to appear within the pressure range from 6.0 to 7.3 GPa (Belo et al., 2010), is also argued. The changes in the Raman spectra have been shown to be continuous in all the pressure ranges studied.

Research on the Second Phase of Spray Forming Al-8.5Fe-1.3V-1.7Si Aluminum Alloy

2014 ◽  
Vol 886 ◽  
pp. 36-40
Author(s):  
Rong Hua Zhang ◽  
Bao Hong Zhu ◽  
Xiao Ping Zheng
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Room Temperature ◽  
Spray Forming ◽  
Heating Process ◽  
Second Phase ◽  
Transmission Electron ◽  
Second Phases

Heat-resistant Al-8.5Fe-1.3V-1.7Si aluminum alloys were prepared by spray forming technique. The phase transition of deposited alloys from room temperature to 500°C was measured by Differential Scanning Calorimeter. The organization and the second phases of the alloys were observed and studied by transmission electron microscopy. The research results show that No endothermic peak appears in the deposited alloys during heating process, there is no phase transition occur in the alloy during the heating process from room temperature to 500°C. The deposited alloys mainly include α-Al and α-Al12(Fe,V)3Si phase. Under the transmission electron microscopy, there are also a small amount of slug, fan-shaped, needle-like, block, strip second phases, these phases are Al12Fe3Si, Al8Fe2Si, θ-Al13Fe4, Al9FeSi3, Al6Fe.

Effect of Growth Conditions on Structural and Electrical Properties of Pb(ZrxTi1−x)O3 layers grown by peroxide MBE

2007 ◽  
Vol 1034 ◽  
Author(s):  
Natalia Izyumskaya ◽  
V. Avrutin ◽  
X. Gu ◽  
B. Xiao ◽  
S. Chevtchenko ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Phase Composition ◽  
Electrical Properties ◽  
Ferroelectric Properties ◽  
Field Measurements ◽  
Growth Conditions ◽  
Second Phase ◽  
Conductive Atomic Force Microscopy ◽  
Structural And Electrical Properties ◽  
Pzt Films

AbstractPb(ZrxTi1−x)O3 (PZT) films were grown by molecular beam epitaxy using hydrogen peroxide as a source of reactive oxygen. Phase composition as well as structural and electrical properties of the films were studied by x-ray diffractometry, scanning and transmission electron microscopy, conductive atomic force microscopy, and electrical (I-V and polarization-field) measurements. The hydrogen peroxide pressure was found to control the phase composition of the films. Excess peroxide leads to PbO inclusions in PZT layers, whereas deficiency results in the TiO2 or the ZrO2 phase. The second-phase inclusions can be responsible for high leakage current in the films. Precise control over the peroxide pressure is imperative for single-phase PZT films with good ferroelectric properties.

Effects of Mn Doping on Dielectric Properties of BSTN Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 72-74
Author(s):  
Xin Cheng ◽  
Zong Hui Zhou
Keyword(s):  
Phase Transition ◽  
Phase Composition ◽  
Transition Temperature ◽  
Dielectric Properties ◽  
Phase Transition Temperature ◽  
Tungsten Bronze ◽  
Dielectric Constants ◽  
Composite Ceramics ◽  
Mn Doping ◽  
Applied Frequency

The effects of Mn doping on the phase composition and dielectric properties of (1-x)BaO·xSrO·0.7TiO2·0.3Nb2O5 (BSTN) composite ceramics was investigated. The results showed that the dielectric constants of 0.7BaO·0.3SrO·(0.7-z)TiO2·0.3Nb2O5·zMnO2 (BSTNM) composite ceramics basically decreases as the content of doped MnO2 increases at the same applied frequency, while tanδ decreases when value z≤0.01 but increases when value z>0.01. The phase transition temperature of tungsten bronze phase in BSTNM composite ceramics increases with the increase of value z.

Phase Field Study for Self-Assemble of the Second Phase Particles in Coherent Phase Transition

2007 ◽  
pp. 583-586
Author(s):  
Jin You Kim ◽  
Jong Kyu Yoon ◽  
Yoo Chan Kim ◽  
Hyunn Kwang Suck ◽  
Ki Bae Kim ◽  
...  
Keyword(s):  
Phase Transition ◽  
Field Study ◽  
Phase Field ◽  
Second Phase ◽  
Coherent Phase ◽  
Second Phase Particles

An Improvement in Sintering Property of β-Tricalcium Phosphate by Addition of Calcium Pyrophosphate and Calcium Carbonate

2005 ◽  
Vol 475-479 ◽  
pp. 2359-2362 ◽  
Author(s):  
Xin Long Wang ◽  
Hong Song Fan ◽  
Xing Dong Zhang
Keyword(s):  
Phase Transition ◽  
Compressive Strength ◽  
Calcium Carbonate ◽  
Tricalcium Phosphate ◽  
Degradation Rate ◽  
Calcium Pyrophosphate ◽  
Sintering Behavior ◽  
Second Phase ◽  
Lower Temperature

b-tricalcium phosphate(TCP, Ca3(PO4)2) ceramics are preferred as a bioceramics because of its chemical stability and reasonable degradation rate in vivo, but it is difficult to obtain b-TCP ceramics with high compressive strength at lower temperature than that of phase transition to a-TCP. In this study, the sintering behavior of TCP, Ca2P2O7-doped TCP, and CaCO3-doped TCP in the range of 2wt%~5wt% were investigated respectively. Phase transition of pure TCP took place between 1100°C to 1150°C, and pure b-TCP ceramics could achieve a compressive strength of only 3MPa. However, calcium pyrophosphate (CPP, Ca2P2O7) additive prevented the transformation of b-TCP to a-TCP, but the second phase of CPP was observed in the resultant ceramics. Phase transition of TCP ceramics by addition of both CPP and calcium carbonate (CC, CaCO3) took place between 1200°C to 1250°C and the resultant TCP ceramics had few impurity of CPP. By adding CPP and CC to TCP, final ceramics with compressive strength over 12MPa could be obtained when sintered at 1200°C for 2hrs.

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