Quadrupole Coupling in Ammonium Metaperiodate at Low Temperature

2002 ◽  
Vol 57 (8) ◽  
pp. 661-662 ◽  
Author(s):  
S. L. Segel ◽  
R. J. C. Brown ◽  
E. E. Ylinen ◽  
L. P. Ingman ◽  
T. J. Bastow
Keyword(s):  
Low Temperature ◽  
Low Temperatures ◽  
Quadrupole Coupling ◽  
Temperature Dependences ◽  
Nuclear Quadrupole

The temperature dependences of the 127I nuclear quadrupole coupling in NH4IO4 and in ND4IO4 are reported. In each salt, the quadrupole coupling decreases to a very small value at low temperatures, and in the case of ND4IO4 passes through zero and changes sign at 87 K.

Anomaly of Nuclear Quadrupole Relaxation in Cu2O Prepared at Low Temperatures

1986 ◽  
Vol 41 (1-2) ◽  
pp. 382-385 ◽  
Author(s):  
J. Kasprzak ◽  
J. Lus ◽  
J. Pietrzak
Keyword(s):  
Temperature Dependence ◽  
Cuprous Oxide ◽  
Thermal Processing ◽  
Low Temperatures ◽  
Room Temperature ◽  
Quadrupole Relaxation ◽  
Temperature Dependences ◽  
Powder Samples ◽  
Nuclear Quadrupole ◽  
Nuclear Quadrupole Relaxation

The 63Cu and 65Cu NQR transitions in powder samples of cuprous oxide have been investigated from 77 to 500 K and at room temperature after annealing up to 1100 K Significant differences in T1 , NQR linewidth Δv, and their temperature dependences were found among the samples prepared in different ways. For C u20 samples obtained in low temperatures (below 380 K), the temperature dependence of T1 below 380 K is o f activation character with Ea = 0.07 eV. These results are interpreted in terms of an electron hopping mechanism. Thermal processing of these samples permits to obtain irreversible electronic state and then the spectroscopic parameters are the same as for the samples obtained in high temperatures (above 1320 K).

Spektroskopische Untersuchungen in der Festkörperchemie, XIII. Temperaturabhängigkeit der 127I-Kernquadrupolkopplung in NH4IO4 und anderen Periodaten / Spectroscopic Investigations in the Solid State Chemistry, XIII. Temperature Dependence of the 127I-Nuclear Quadrupole Coupling in NH4IO4 and other Periodates

1980 ◽  
Vol 35 (11) ◽  
pp. 1349-1354 ◽  
Author(s):  
Paul K. Burkert
Keyword(s):  
Temperature Dependence ◽  
Coupling Constants ◽  
Solid State Chemistry ◽  
Positive Temperature ◽  
Electric Field Gradients ◽  
Field Gradients ◽  
Quadrupole Coupling ◽  
Temperature Dependences ◽  
Nuclear Quadrupole ◽  
Nmr Signals

The temperature dependence of the electric field gradients was measured by I. and II. order quadrupole effects of the 127I NMR signals in scheelite-structured NH4IO4 and RbIO4, in pseudo-scheelite CsIO4 and in N(CH3)4IO4, where rcation > ranion- An interpretation of the anomalous positive temperature dependences of the quadrupole coupling constants in NH4IO4 and in the isostructural NH4ReO4 is proposed.

scholarly journals Low temperature thermodynamics of finite spin-1/2 XX Chain with some distorted links

2019 ◽  
Keyword(s):  
Low Temperature ◽  
Field Dependence ◽  
Low Temperatures ◽  
Numerical Study ◽  
Pair Correlation ◽  
Thermodynamic Characteristics ◽  
Model Parameters ◽  
Stationary States ◽  
Continuous Band ◽  
Temperature Dependences

We present the results of our analytical and numerical study of quantum stationary states and the thermodynamics of exactly solvable finite linear spin-1/2 XX chain with one or two distorted links. The exact dispersion equations for the stationary states with one inverted spin for both cases have been derived. The corresponding spectrum consists of one quasi-continuous band and some localized impurity levels. The analytical inequalities for the values of the critical model parameters describing the appearance of local energy impurity levels above and below quasi-continuous band are obtained and analyzed. The field and the temperature dependences of the main thermodynamic characteristics of these models are studied. It is shown, that the appearance of the localized levels near the distorted links may effect significantly on the thermodynamic properties at low temperatures, leading to the additional singularities in the field and the temperature dependences of the principal thermodynamic characteristics. For example, the field dependence of z-projection of average total spin and the field dependence of the magnetization at zero temperature have the finite jumps associated with the quasi-continuous spectrum, and the impurity levels. The remnants of these jumps at rather low temperature are clearly visible. The average z-projections of the spins of distorted link(s) may decrease with the increasing of the magnetic field for some values of model parameters. The temperature dependence of the specific heat may demonstrate additional maxima at very low temperatures. The complex oscillatory pattern of the time dependence of the dynamical longitudinal pair correlation function and the autocorrelation function is associated with the finiteness of the models and the appearance of associated localized energy levels.

In situ Tensile Experiments at Low Temperatures on Niobium Single Crystals by H.V.E.M.

1975 ◽  
Vol 33 ◽  
pp. 58-59
Author(s):  
F. H. Louchet ◽  
L. P. Kubin
Keyword(s):  
Electron Microscope ◽  
Transition Temperature ◽  
Low Temperature ◽  
Slip System ◽  
Low Temperatures ◽  
Tensile Axis ◽  
Image Intensifier ◽  
Screw Dislocations ◽  
Source Operation

Experiments have been carried out on the 3 MeV electron microscope in Toulouse. The low temperature straining holder has been previously described Images given by an image intensifier are recorded on magnetic tape.The microtensile niobium samples are cut in a plane with the two operative slip directions [111] and lying in the foil plane. The tensile axis is near [011].Our results concern:- The transition temperature of niobium near 220 K: at this temperature and below an increasing difference appears between the mobilities of the screw and edge portions of dislocations loops. Source operation and interactions between screw dislocations of different slip system have been recorded.

INVAR M93

Alloy Digest ◽  
2008 ◽  
Vol 57 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Low Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Low Temperatures ◽  
Bend Strength ◽  
Temperature Performance ◽  
Ni Content ◽  
Precision Alloys ◽  
Ni Alloy

Abstract Invar is an Fe-Ni alloy with 36% Ni content that exhibits the lowest expansion of known metals from very low temperatures up to approximately 230 deg C (445 deg F). Invar M93 is a cryogenic Invar with improved weldability. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear and bend strength as well as fracture toughness and fatigue. It also includes information on low temperature performance as well as forming and joining. Filing Code: FE-143. Producer or source: Metalimphy Precision Alloys.

19F Nuclear Quadrupole Coupling in some Halomethanes

1986 ◽  
Vol 41 (1-2) ◽  
pp. 171-174 ◽  
Author(s):  
M. Frank ◽  
F. Gubitz ◽  
W. Ittner ◽  
W. Kreische ◽  
A. Labahn ◽  
...  
Keyword(s):  
Angular Distribution ◽  
Simple Model ◽  
Temperature Dependence ◽  
Coupling Constants ◽  
Temperature Dependent ◽  
Distribution Method ◽  
Quadrupole Coupling ◽  
Time Differential ◽  
Nuclear Quadrupole

The 19F quadrupole coupling constants in CF4, CHF3, CClF3 and CHClF2 are reported. The measurements were carried out temperature dependent using the time differential perturbed angular distribution method (TDPAD). The temperature dependence can be satisfactorily described in the framework of the Bayer-Kushida theory. A simple model is used to explain the appearance of H-F and Cl-F coupling constants in CHF3/CHClF2 and CClF3, respectively.

FEC-LiTFSI-Pyr1ATFSI Ionic Liquid Electrolyte to Improve Low Temperature Performance of Lithium-Ion Batteries

2014 ◽  
Vol 986-987 ◽  
pp. 80-83
Author(s):  
Xiao Xue Zhang ◽  
Zhen Feng Wang ◽  
Cui Hua Li ◽  
Jian Hong Liu ◽  
Qian Ling Zhang
Keyword(s):  
Low Temperature ◽  
Lithium Ion Batteries ◽  
Low Temperatures ◽  
Freezing Point ◽  
Lithium Ion ◽  
Liquid Electrolyte ◽  
Capacity Retention ◽  
Composite Electrolyte ◽  
Ionic Liquid Electrolyte ◽  
Fluoroethylene Carbonate

N-methyl-N-allylpyrrolidinium bis (trifluoromethanesulfonyl) imide (PYR1ATFSI) with substantial supercooling behavior is synthesized to develop low temperature electrolyte for lithium-ion batteries. Additive fluoroethylene carbonate (FEC) in LiTFSI/PYR1ATFSI/EC/PC/EMC is found that it can reduce the freezing point. LiFePO4/Li coin cells with the FEC-PYR1ATFSI electrolyte exhibit good capacity retention, reversible cycling behavior at low temperatures. The good performance can be attributed to the decrease in the freezing point and the polarization of the composite electrolyte.

Sign in / Sign up

Export Citation Format

Share Document