Role of Mn in controlling the dielectric loss and ageing effect in Pb(Zn1/3Nb2/3)O3–Pb(Fe2/3W1/3)O3–Pb(Fe1/2Nb1/2)O3

1998 ◽  
Vol 33 (8) ◽  
pp. 1991-1995 ◽  
Author(s):  
R NATARAJAN ◽  
R NATARAJAN
Keyword(s):  
Dielectric Loss ◽  
Ageing Effect

The Dielectric Loss of Single Crystal and Polycrystalline TiO2

1997 ◽  
Vol 500 ◽  
Author(s):  
Xiaoru Wang ◽  
Alan Templeton ◽  
Stuart J. Penn ◽  
Neil McN. Alford
Keyword(s):  
Dielectric Loss ◽  
Single Crystal ◽  
Mixed Valence ◽  
Dielectric Materials ◽  
Oxygen Stoichiometry ◽  
Ion Conductor ◽  
Microwave Dielectric ◽  
Valence States ◽  
Oxygen Ion Conductor

ABSTRACTThe dielectric loss of single crystal and polycrystalline TiO2 has been studied. In polycrystalline TiO2 the dielectric loss is determined by both the microstructure and by the oxygen stoichiometry. Experiments have been carried out to determine the influence of both the microstructure (particularly porosity) and the oxygen stoichiometry. The TiO2 powder has been doped with partially stabilised zirconia, an oxygen ion conductor, in order to modify the oxygen stoichiometry. Sintered discs have been examined for loss as a function zirconia doping, pore volume and as a function of temperature. The behaviour of the doped and undoped titania powders is significantly different. Since many microwave dielectric materials contain Ti eg Ba-Ti-O, Ba-Nd-Ti-O, (Ba-RE-Ti-O, RE=Rare Earth), Zr-Sn-Ti-O etc it is essential to understand the role of the titanium, particularly as it can exist in mixed valence states, and the role of oxygen and its influence on the dielectric loss.

The utilization of time-resolved dielectric loss to probe the role of the surface in heterogeneous photochemistry

1986 ◽  
Vol 82 (12) ◽  
pp. 3625 ◽  
Author(s):  
Christopher J. Dobbin ◽  
Alan R. McIntosh ◽  
James R. Bolton ◽  
Zoran D. Popovic ◽  
John R. Harbour
Keyword(s):  
Dielectric Loss ◽  
Time Resolved

scholarly journals Anomalous Behaviour of Antarctic ice Cores Studied by Electrical and Mechanical Damping Measurements

1982 ◽  
Vol 3 ◽  
pp. 307-311 ◽  
Author(s):  
R. Vassoille ◽  
J. Perez ◽  
J. Tatibouet ◽  
P. Duval ◽  
M. Maccagnan
Keyword(s):  
Point Defects ◽  
Ice Cores ◽  
Anomalous Behaviour ◽  
Ageing Effect ◽  
Polar Ice ◽  
Electrical Measurements ◽  
Coastal Site ◽  
New Information ◽  
Friction Measurements

In order to obtain new information concerning the anomalous properties of Antarctic ice previously observed through electrical measurements, we have studied specimens from a coastal site by means of internal friction measurements in the 1 Hz range. The results have been compared to previous ones obtained with polar ice from Dome C and electrical measurements have been made on the same samples in order to confirm the anomalous behaviour of such material.Two possible explanations of the anomalous properties of polar ice are discussed, namely the role of impurities and the ageing effect. It seems improbable that impurities could be responsible for such properties due to their low concentration. Some experiments, however, lead us to interpret the behaviour of polar ice in terms of modifications with time of the concentration and distribution of intrinsic point defects present at the beginning of the existence of the ice microcrystals

scholarly journals Investigation on the role of the dielectric loss in metamaterial absorber

2010 ◽  
Vol 18 (7) ◽  
pp. 6598 ◽  
Author(s):  
ChengGang Hu ◽  
Xiong Li ◽  
Qin Feng ◽  
Xu’Nan Chen ◽  
XianGang Luo
Keyword(s):  
Dielectric Loss ◽  
Metamaterial Absorber

scholarly journals Anomalous Behaviour of Antarctic ice Cores Studied by Electrical and Mechanical Damping Measurements

1982 ◽  
Vol 3 ◽  
pp. 307-311 ◽  
Author(s):  
R. Vassoille ◽  
J. Perez ◽  
J. Tatibouet ◽  
P. Duval ◽  
M. Maccagnan
Keyword(s):  
Point Defects ◽  
Ice Cores ◽  
Anomalous Behaviour ◽  
Ageing Effect ◽  
Polar Ice ◽  
Electrical Measurements ◽  
Coastal Site ◽  
New Information ◽  
Friction Measurements

In order to obtain new information concerning the anomalous properties of Antarctic ice previously observed through electrical measurements, we have studied specimens from a coastal site by means of internal friction measurements in the 1 Hz range. The results have been compared to previous ones obtained with polar ice from Dome C and electrical measurements have been made on the same samples in order to confirm the anomalous behaviour of such material.Two possible explanations of the anomalous properties of polar ice are discussed, namely the role of impurities and the ageing effect. It seems improbable that impurities could be responsible for such properties due to their low concentration. Some experiments, however, lead us to interpret the behaviour of polar ice in terms of modifications with time of the concentration and distribution of intrinsic point defects present at the beginning of the existence of the ice microcrystals

scholarly journals Mobility and transformation of CdSe/ZnS quantum dots in soil: Role of the capping ligands and ageing effect

Chemosphere ◽  
2020 ◽  
Vol 254 ◽  
pp. 126868 ◽  
Author(s):  
A. Carboni ◽  
A. Gelabert ◽  
G. Charron ◽  
S. Faucher ◽  
G. Lespes ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Ageing Effect ◽  
Capping Ligands

Carbon-Induced UV Sensitivity in Aluminum Nitride

1998 ◽  
Vol 4 (S2) ◽  
pp. 570-571
Author(s):  
Y. Berta ◽  
R. A. Gerhardt
Keyword(s):  
Dielectric Loss ◽  
Aluminum Nitride ◽  
Uv Irradiation ◽  
High Performance ◽  
High Energy ◽  
Multichip Modules ◽  
Low Oxygen ◽  
Carbon Impurities ◽  
Ultimate Purpose

Aluminum nitride, translucent, calcia-sintered and hot pressed, with its superior thermal properties has applications in high performance electronic devices such as multichip modules. In these applications, A1N is exposed to high energy electromagnetic sources which could alter its properties; for example, upon UV irradiation, thermal conductivity drops and dielectric loss increases. These observations indicate that the UV altered properties are due to the presence of impurities. The early studies concentrated primarily on oxygen doped samples, which photodarken upon UV exposure; the role of other impurities was not considered.In the current work, we consider the role of carbon in the microstructure of two very low oxygen content (< 0.3 wt %), carbon-containing samples, labeled B and E, for the ultimate purpose of 3 determining the mechanism by which carbon impurities affect the properties of A1N. Previous work on these samples correlated higher carbon content with a lower increase in the dielectric loss factor, after UV irradiation,

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