Electrical resistivity evidence of a ferroelecteic phase transition in potassium nitrate

2007 ◽  
Vol 2 (2) ◽  
Author(s):  
RK Nkum
Keyword(s):  
Phase Transition ◽  
Electrical Resistivity ◽  
Potassium Nitrate

scholarly journals Cooper Pair-Like Systems at High Temperature and their Role on Fluctuations Near the Critical Temperature

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3216-3219 ◽  
Author(s):  
M. Ausloos ◽  
S. Dorbolo
Keyword(s):  
Phase Transition ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Critical Temperature ◽  
Oxygen Diffusion ◽  
Cooper Pair ◽  
Anomalous Behavior ◽  
Anomalous Effect ◽  
Linear Temperature ◽  
Ybco Sample

A logarithmic behavior is hidden in the linear temperature regime of the electrical resistivity R(T) of some YBCO sample below 2T c where "pairs" break apart, fluctuations occur and "a gap is opening". An anomalous effect also occurs near 200 K in the normal state Hall coefficient. In a simulation of oxygen diffusion in planar 123 YBCO, an anomalous behavior is found in the oxygen-vacancy motion near such a temperature. We claim that the behavior of the specific heat above and near the critical temperature should be reexamined in order to show the influence and implications of fluctuations and dimensionality on the nature of the phase transition and on the true onset temperature.

14N and 39K Nuclear Quadrupole Coupüng in KNO3

1990 ◽  
Vol 45 (3-4) ◽  
pp. 459-463 ◽  
Author(s):  
T. J. Bastow ◽  
S. N. Stuart
Keyword(s):  
Phase Transition ◽  
Nuclear Magnetic Resonance ◽  
Room Temperature ◽  
Potassium Nitrate ◽  
Nuclear Quadrupole Interaction ◽  
Coupling Constants ◽  
Disorder Phase Transition ◽  
Nuclear Quadrupole ◽  
T Values ◽  
Asymmetry Parameters

Abstract The nuclear quadrupole interaction tensors of 14N and 39K in potassium nitrate at room temperature have been determined from nuclear magnetic resonance (NMR) rotation studies of single crystals at 9.4 T. Values for the coupling constants and asymmetry parameters at 296 K are:14N: e2 qQ/h = 751 kHz, η = 0.022; 39K: e2 qQ/h = 1326kHz, η = 0.171. The temperature dependence, on approaching the order-disorder phase transition near 401 K, is linear.

Electrical resistivity of in the vicinity of quantum phase transition

2005 ◽  
Vol 359-361 ◽  
pp. 71-73 ◽  
Author(s):  
Shintaro Nakamura ◽  
Harufumi Yamamoto ◽  
Motoki Endo ◽  
Haruyoshi Aoki ◽  
Tsutomu Nojima ◽  
...  
Keyword(s):  
Phase Transition ◽  
Electrical Resistivity ◽  
Quantum Phase Transition ◽  
Quantum Phase

Phase transition regulation and piezoelectric performance optimization of fresnoite crystal for high temperature acceleration sensing

2021 ◽  
Author(s):  
Chao Jiang ◽  
Caizi Zhang ◽  
Fangfei Li ◽  
Li Sun ◽  
Yanlu Li ◽  
...  
Keyword(s):  
Phase Transition ◽  
Electrical Resistivity ◽  
High Temperature ◽  
Performance Optimization ◽  
Elevated Temperatures ◽  
Piezoelectric Response ◽  
Potential Candidate ◽  
High Electrical Resistivity ◽  
Sensing Applications ◽  
Piezoelectric Performance

Fresnoite crystal, Ba2TiSi2O8 (BTS), is a potential candidate for high temperature piezoelectric sensing applications, due to high electrical resistivity and strong piezoelectric response at elevated temperatures. However, anomalies of electro-elastic...

Rubber Processability Index Using Electrical Resistivity

1992 ◽  
Vol 65 (3) ◽  
pp. 660-672
Author(s):  
S. Shiga
Keyword(s):  
Phase Transition ◽  
Electrical Resistivity ◽  
Percolation Theory ◽  
Transition Point ◽  
Mixing Time ◽  
Sudden Change ◽  
Phase Transition Point ◽  
The Other ◽  
Special Equipment ◽  
Popular Method

Abstract It may not be realistic to expect a single processability index to be useful for every feature of rubber mixing due to the complexity of its mechanisms. Many processability indices have been proposed. One can find properties available to define the indices in Table I. The indices can be conceptually classified into two categories. One is founded on the singularity of some properties at the minimum mixing time. The compound mixed over this time is Theologically homogeneous in contrast to that mixed insufficiently. Therefore, this time is a phase-transition point. Not all, but most of the properties indicate the sudden change in the time-derivatives characteristic to singular points. After the time, the change becomes smaller. The other is founded on the properties of final compounds, which could be assumed as existing in a pseudoequilibrium state. Electrical volume resisitivity (resisitivity, hereafter) is chosen for this purpose. It looks simple and suitable for practice, i.e., in rubber factories. Actually, as reported by Boonstra, the measurement requires skill in addition to special equipment and is not a popular method. Nevertheless, we have used it to express the processability and, more generally, to clarify the mixing mechanism. There are three reasons for this methodology: first, we find that EPR, the object of our study, apparently shows constant minimum mixing time; second, the pseudoequilibrium-like resistivity is parallel to other processability indices, namely, the larger the resistivity, the worse the processability as described in Reference 1; third, the resistivity directly corresponds to the percolation theory. Of course, other processability indices have their own theoretical origins. However, properties other than resistivity can not be quantitatively supported by theory because of the complexity of mixing. The exceptions are microscopic methods as exemplified by the counting of large agglomerates and their size distribution, but these are more tedious and require more skill.

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