High Temperature Dielectric Constants of Rubidium Halides

1972 ◽  
Vol 50 (10) ◽  
pp. 1053-1054 ◽  
Author(s):  
Suresh Chandra ◽  
Jai Prakash
Keyword(s):  
Dielectric Constant ◽  
High Temperature ◽  
Melting Point ◽  
Standing Wave ◽  
Room Temperature ◽  
Dielectric Constants ◽  
Wave Technique

The high temperature dielectric constants of RbCl, RbBr, and RbI are measured at 24.6 GHz from room temperature to near melting point. A standing wave technique has been used. The dielectric constant of RbBr is observed to increase at a faster rate than that of RbCl and RbI.

High temperature dielectric constant of KI

1969 ◽  
Vol 47 (9) ◽  
pp. 969-973 ◽  
Author(s):  
Suresh Chandra
Keyword(s):  
Dielectric Constant ◽  
Thermal Expansion ◽  
High Temperature ◽  
Melting Point ◽  
Thermal Expansion Coefficient ◽  
Standing Wave ◽  
Expansion Coefficient ◽  
Room Temperature ◽  
Polarization Effects ◽  
Complex Polarization

The dielectric constant of KI crystal has been measured at 23.6 GHz from room temperature to near the melting point. A K-band microwave standing wave ratio technique was used for this purpose to avoid complex polarization effects. It was found that the dielectric constant of KI increases more rapidly than for KCl and KBr, presumably due to its larger thermal expansion coefficient at high temperatures.

THE COMPLEX DIELECTRIC CONSTANT OF SOLUTIONS OF TRIMETHYLPENTANE AND NITROBENZENE NEAR THE CONSOLUTE TEMPERATURE

1961 ◽  
Vol 39 (3) ◽  
pp. 526-534 ◽  
Author(s):  
B. D. Ripley ◽  
R. McIntosh
Keyword(s):  
Dielectric Constant ◽  
Phase Separation ◽  
Standing Wave ◽  
Applied Field ◽  
Coaxial Line ◽  
Dielectric Constants ◽  
Complex Dielectric Constant ◽  
Experimental Procedure ◽  
Chemical Systems ◽  
Consolute Temperature

The complex dielectric constants of three compositions of trimethylpentane and nitrobenzene have been measured as a function of temperature for a range near the consolute temperature. The frequency employed was 3300 Mc/sec. The experimental procedure involved the study of the standing wave established in a coaxial line. The chemical systems showed maxima in both the real and imaginary parts of the complex dielectric constant at temperatures above those at which phase separation occurs. The finding of Semenchenko and Azimov is thus confirmed. A discussion of the validity of applying thermodynamic formulae to dielectrics showing loss is given and some qualitative remarks are offered concerning the change of the systems as they are cooled. These remarks are based upon the effect of the applied field upon the entropy of the solutions.

ARSENIDES OF THE TRANSITION METALS: II. THE NICKEL ARSENIDES

1957 ◽  
Vol 35 (10) ◽  
pp. 1205-1215 ◽  
Author(s):  
R. D. Heyding ◽  
L. D. Calvert
Keyword(s):  
High Temperature ◽  
Melting Point ◽  
Transition Metals ◽  
Stability Region ◽  
Room Temperature ◽  
Metastable Phase ◽  
The Other ◽  
Incongruent Melting ◽  
Diffraction Patterns ◽  
The Stability

Alloys of nickel and arsenic containing up to 60% As by weight have been studied by means of room temperature and high temperature Debye-Scherrer diagrams. Three compounds have been identified: Ni5As2, Ni12−xAs8 (maucherite), and NiAs (niccolite). The first of these is homogeneous from Ni5As2 to Ni4.8A2 at room temperature, and to Ni4.6As2 above 250 °C., while the latter is homogeneous from NiAs to Ni0.95As. Contrary to expectations the stability region of the compound Ni12−xAs8 is very narrow, and occurs at Ni11As8 rather than at Ni3As2. Evidence is presented in support of Hansen's contention that this compound has an incongruent melting point. Alloys in the region corresponding to Ni4.6As2 undergo two transitions below 200 °C, one of which is martensitic and produces a metastable phase, while the other is believed to result in the formation of a new compound, as yet unidentified. The diffraction patterns are discussed in some detail.

In—Line Measurement Of High Temperature Dielectric Constant In The Process Of Sintering

1996 ◽  
Vol 430 ◽  
Author(s):  
Zhou Jian ◽  
Cheng Jiping ◽  
Tang Yuling ◽  
Qiu Jinyu
Keyword(s):  
Dielectric Constant ◽  
High Temperature ◽  
Resonant Cavity ◽  
Ceramic Materials ◽  
Dielectric Constants ◽  
Experimental Results ◽  
Cavity Method ◽  
Experimental Basis ◽  
Ceramic Samples ◽  
Line Measurement

AbstractIn this paper, a resonant cavity method is developed and some experimental results for measuring dielectric constants of ceramic samples (e. g. Al2O3) under different sintering temperatures are reported. The experiments show that this method has higher precision and good prospects of in—line monitoring the high temperature dielectric constant in the process of raising the temperature of the samples. These results provide some scientific experimental basis for physical research of ceramic materials.

Dielectric Properties of β-SiAlON at High Temperature Using Perturbation Method

2008 ◽  
Vol 403 ◽  
pp. 121-123 ◽  
Author(s):  
Young Hoon Seong ◽  
Ha Neul Kim ◽  
Do Kyung Kim
Keyword(s):  
Dielectric Constant ◽  
High Temperature ◽  
Dielectric Properties ◽  
Perturbation Method ◽  
Hot Pressing ◽  
Room Temperature ◽  
Tangent Loss ◽  
Resonator Method

-SiAlON with various z-values (z = 0.5~4.0) were produced by hot pressing. The dielectric properties (dielectric constant and tangent loss) of -SiAlON were characterized by the post-resonator method at room temperature and by the perturbation method from room temperature to 1200 oC at 2.45 GHz, respectively. Effect of z-values and temperatures with -SiAlON were investigated.

Electrical Properties of Bi(In,Ga,Sc)O3-PbTiO3 Piezoelectric Ceramics

2013 ◽  
Vol 364 ◽  
pp. 794-798 ◽  
Author(s):  
Yi Chen ◽  
Jian Guo Zhu ◽  
Ding Quan Xiao
Keyword(s):  
Dielectric Constant ◽  
High Temperature ◽  
Electrical Properties ◽  
Lead Titanate ◽  
Room Temperature ◽  
Electromechanical Coupling ◽  
Piezoelectric Properties ◽  
Electromechanical Coupling Coefficient ◽  
Piezoelectric Devices ◽  
Dielectric And Piezoelectric Properties

The gallium and indium double-modified bismuth scandate-lead titanate (1-x)Bi (In0.20Ga0.05Sc0.75)O3-xPbTiO3((1-x)BIGS-xPT,x=0.55-0.70) ceramics were prepared by using conventional ceramic technique. (1-x)BIGS-xPT ceramics for nearx=0.60 exhibits an evident enhancement in room temperature dielectric and piezoelectric properties, with dielectric constantε, piezoelectric constantd33, planar electromechanical coupling coefficientkpand Curie temperatureTCof 1100, 295 pC/N, 0.43 and 435 °C, respectively. TheTCof (1-x)BIGS-xPT is in the range of 425-530 °C for the compositions investigated. The combination of highTCand excellent piezoelectric activity suggest that the (1-x)BIGS-xPT ceramics are usable candidate materials for high temperature piezoelectric devices applications.

scholarly journals Huge values of room-temperature dielectric constants in pellets of poly(3-methylthiophene)

2004 ◽  
Vol 19 (7) ◽  
pp. 2068-2071
Author(s):  
S. Moraes ◽  
L. Walmsley ◽  
E.C. Pereira ◽  
A.A. Correa
Keyword(s):  
Dielectric Constant ◽  
Charge Density Wave ◽  
Room Temperature ◽  
Density Wave ◽  
Low Frequency ◽  
Temperature Data ◽  
Dielectric Constants ◽  
Wave Characteristic ◽  
Rc Circuit ◽  
A Charge

Room temperature data of impedance and phase angle in pellets of electrochemically synthesized ClO4− doped poly(3-methylthiophene) (P3MT) were analyzed assuming the sample being represented by a parallel resistor-capacitor (RC) circuit or by a series RC circuit. The last assumption proved to be the correct one, and to confirm it we use the sample as the RC component of a resistor-capacitor-inductor series resonator. We discuss the possibility of this RC series behavior to be due to a charge-density wave characteristic also evidenced from the huge values of the low-frequency dielectric constant of the system.

Preparation and Dielectric Properties of Cu/PVDF Composite Films

2014 ◽  
Vol 1035 ◽  
pp. 417-421 ◽  
Author(s):  
Jian Wen Zhai ◽  
Ya Jun Wang ◽  
Jian Lou Deng ◽  
Chang Gen Feng
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Room Temperature ◽  
Volume Fraction ◽  
Composite Films ◽  
Interfacial Polarization ◽  
Dielectric Constants ◽  
Pvdf Film ◽  
Continuous Increase ◽  
Better Than

nanoand micro size Cu were employed separately and investigated comparatively. Different volume fraction of Cu was added into PVDF film in order to investigate the content of filler effect on the dielectric properties of polymer composites. XRD and SEM were used to analyze the crystalline phase and microstructure of the films. The results show that two sizes of Cu have the same peak features, and with the continuous increase of the content of Cu, it disperse better in PVDF. The dielectric constant (ε) of the composite containing 16 vol% micro-CCTO filler is 16 at 100 Hz and room temperature, and its dielectric loss (tanδ) is only 0.15, which is substantially better than others. Besides, for 18 vol% nanoCu/PVDF composite tanδis 0.25 andεis 18 at 100 Hz. Moreover,εand tanδof nanoCu/PVDF composite are both higher than those of micro-Cu/PVDF. Analysis shows that the composites with nanoCu have higher dielectric constants, which is mainly from the interfacial polarization.

Synthesis and Characterization of Azobenzene-Containing Polydiacetylene Polymers

2014 ◽  
Vol 976 ◽  
pp. 46-51
Author(s):  
Esthela Albarrán Preza ◽  
Enrique Vigueras-Santiago ◽  
Susana Hernández López
Keyword(s):  
Dielectric Constant ◽  
Room Temperature ◽  
Main Chain ◽  
Dielectric Constants ◽  
Electronic Density ◽  
Polar Species ◽  
Acceptor Group ◽  
Covalently Bonded ◽  
Donor Acceptor

Polydiacetylenes are a type of highly conjugated polymers, and highly polar species are obtained when these polymers contain donor-acceptor azobenzene entities. In this paper the synthesis, characterization and evaluation of the dielectric constant of two polydiacetylenes containing azobenzenes as pendant groups are discussed. The Azobenzene chromophores are covalently bonded to the main chain, and their polarity is defined by an electro-donor (amine) and an electro-acceptor group (nitro or chlorine) bonded to the ends of a conjugated azobenzene structure. Both polymers were processed into plates of 1cm diameter x 0.674 mm thickness using a thermo mechanic technique. Their dielectric constants were evaluated respect to the temperature in a range of frequency of 110 MHz-1.32 GHz, from room temperature to close to their respective Tg. The dielectric constant for the polymer containing the nitro group was higher than it for polymer containing the chloride atom at all temperatures. It is discussed in terms of the ability to nitro and chloride to attract electronic density.

High-Temperature Dielectric Properties of Polycrystalline Ceramics

1988 ◽  
Vol 124 ◽  
Author(s):  
W. W. Ho
Keyword(s):  
High Temperature ◽  
Dielectric Properties ◽  
Volume Expansion ◽  
Room Temperature ◽  
Experimental Methods ◽  
Dielectric Constants ◽  
Amorphous Phases ◽  
Temperature Loss ◽  
Polycrystalline Ceramics ◽  
Impurity Doping

ABSTRACTExperimental methods for determining the high-temperature millimeter-wave dielectric properties of solids are described and the data obtained on a wide variety of polycrystalline ceramics are reviewed. In general, the observed increase in dielectric constants with temperature can be modeled with a macroscopic dielectric virial expansion and shown to be primarily caused by an increase in polarizability due to volume expansion. The room-temperature loss tangents in low-absorption ceramics are probably caused by impurity doping of the primary and secondary crystalline phases at grain junctions and along grain boundaries. The rapid increase in loss tangent at high temperatures commonly observed in polycrystalline ceramics is associated with softening of intergranular amorphous phases resulting in an increase in localized electrical conductivity.

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