High-pressure spectroscopy studies on crystal fields and local structures ofPr3+inGdCl3

2003 ◽  
Vol 67 (12) ◽  
Author(s):  
ChunMao Li ◽  
Kevin L. Bray ◽  
YongRong Shen
Keyword(s):  
High Pressure ◽  
Crystal Fields ◽  
Local Structures ◽  
Spectroscopy Studies

scholarly journals Pressure-Dependent Clustering in Ionic-Liquid-Poly (Vinylidene Fluoride) Mixtures: An Infrared Spectroscopic Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2099
Author(s):  
Teng-Hui Wang ◽  
Wei-Xiang Wang ◽  
Hai-Chou Chang
Keyword(s):  
High Pressure ◽  
High Pressures ◽  
Vinylidene Fluoride ◽  
Ambient Pressure ◽  
Infrared Spectroscopic Study ◽  
Research Attention ◽  
Nanoscale Structures ◽  
Local Structures ◽  
Poly Vinylidene Fluoride ◽  
Hydrogen Bonded

The nanostructures of ionic liquids (ILs) have been the focus of considerable research attention in recent years. Nevertheless, the nanoscale structures of ILs in the presence of polymers have not been described in detail at present. In this study, nanostructures of ILs disturbed by poly(vinylidene fluoride) (PVdF) were investigated via high-pressure infrared spectra. For 1-(2-hydroxyethyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([HEMIm][TFSI])-PVdF mixtures, non-monotonic frequency shifts of the C4,5-H vibrations upon dilution were observed under ambient pressure. The experimental results suggest the presence of microheterogeneity in the [HEMIm][TFSI] systems. Upon compression, PVdF further influenced the local structure of C4,5–H via pressure-enhanced IL–PVdF interactions; however, the local structures of C2–H and hydrogen-bonded O–H were not affected by PVdF under high pressures. For choline [TFSI]–PVdF mixtures, PVdF may disturb the local structures of hydrogen-bonded O–H. In the absence of the C4,5–H⋯anion and C2–H⋯anion in choline [TFSI]–PVdF mixtures, the O–H group becomes a favorable moiety for pressure-enhanced IL–PVdF interactions. Our results indicate the potential of high-pressure application for designing pressure-dependent electronic switches based on the possible changes in the microheterogeneity and electrical conductivity in IL-PVdF systems under various pressures.

scholarly journals Polymer matrix ferroelectric composites under pressure: Negative electric capacitance and glassy dynamics

2019 ◽  
Vol 42 (9) ◽  
Author(s):  
Szymon Starzonek ◽  
Aleksandra Drozd-Rzoska ◽  
Sylwester J. Rzoska ◽  
Kena Zhang ◽  
Emilia Pawlikowska ◽  
...  
Keyword(s):  
High Pressure ◽  
Relaxation Time ◽  
Barium Strontium Titanate ◽  
Atmospheric Pressure ◽  
Polyvinylidene Difluoride ◽  
Broadband Dielectric Spectroscopy ◽  
Electric Capacitance ◽  
Barium Strontium ◽  
Spectroscopy Studies ◽  
Pressure Changes

Abstract. This report presents the results of high-pressure and broadband dielectric spectroscopy studies in polyvinylidene difluoride (PVDF) and barium strontium titanate (BST) microparticles composites (BST/PVDF). It shows that the Arrhenius behaviour for the temperature-related dynamics under atmospheric pressure is coupled to Super-Arrhenius/Super-Barus isothermal pressure changes of the primary relaxation time. Following these results, an explanation of the unique behaviour of the BST/PVDF composite is proposed. Subsequently, it is shown that when approaching the GPa domain the negative electric capacitance phenomenon occurs. Graphical abstract

scholarly journals X-ray diffraction and Raman spectroscopy studies of high-pressure polymorphs ofL- andDL-serine

2006 ◽  
Vol 62 (a1) ◽  
pp. s255-s255
Author(s):  
E. Boldyreva ◽  
T. Drebushchak ◽  
H. Sowa ◽  
S. Goryainov ◽  
V. Chernyshev ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
High Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spectroscopy Studies

Synchrotron X-ray Diffraction and Infrared Spectroscopy Studies of C60H18under High Pressure

2010 ◽  
Vol 1 (4) ◽  
pp. 714-719 ◽  
Author(s):  
Honglei Ma ◽  
Xuemei Zhang ◽  
Bingbing Liu ◽  
Quanjun Li ◽  
Qifeng Zeng ◽  
...  
Keyword(s):  
High Pressure ◽  
Infrared Spectroscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Spectroscopy Studies

Structure and phase characteristics of amorphous boron–carbon–nitrogen under high pressure and high temperature

2001 ◽  
Vol 16 (4) ◽  
pp. 1178-1184 ◽  
Author(s):  
Jianyu Huang ◽  
Yuntian T. Zhu ◽  
Hirotaro Mori
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Atomic Ratio ◽  
Nominal Composition ◽  
Amorphous Boron ◽  
Epitaxial Relationship ◽  
Spectroscopy Studies ◽  
Nanocrystalline Composite ◽  
Electron Energy Loss ◽  
Boron Carbon

An amorphous boron–carbon–nitrogen (a-BCN) phase was synthesized by ball milling of a mixture of hexagonal BN (h-BN) and graphite with a nominal composition of (BN)0.5C0.5 in atomic ratio. Electron energy-loss spectroscopy studies indicated that the bonding of the a-BCN is in an sp2 configuration and the mixing between the BN and the C species was achieved at a nanometer scale, but the a-BCN phase was more likely a mechanical mixture rather than a chemical mixture. High-pressure and high-temperature (HPHT) treatment at 7.7 GPa and 2300 °C of the a-BCN phase resulted in complete segregation of the carbon and BN species, forming a nanocrystalline composite material comprising cubic BN (c-BN), amorphous carbon, and turbostratic graphite. The grain size of the c-BN phase was about 70 nm. No mutual solubilities between c-BN and carbon were found, and the two different species (C and BN) were well separated. An epitaxial relationship, i.e., the (0002) planes of graphite being parallel to the (111) planes of c-BN, was also found. The formation of ternary BCN phases was never found in the present experiment. Our experimental results also suggest the possibility of synthesizing c-BN grains encapsulated with graphite under controlled HPHT conditions.

scholarly journals Microstructure and spectroscopy studies on cubic boron nitride synthesized under high-pressure conditions

2002 ◽  
Vol 14 (44) ◽  
pp. 10983-10988 ◽  
Author(s):  
L C Nistor ◽  
S V Nistor ◽  
G Dinca ◽  
P Georgeoni ◽  
J Van Landuyt ◽  
...  
Keyword(s):  
High Pressure ◽  
Boron Nitride ◽  
Cubic Boron Nitride ◽  
Spectroscopy Studies
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