Physical and electrical properties of combustion synthesized NASICON type Na3Cr2(PO4)3 crystallites: Effect of glycine molar ratios

2011 ◽  
Vol 130 (3) ◽  
pp. 862-869 ◽  
Author(s):  
Lakshmi Vijayan ◽  
Rajesh Cheruku ◽  
G. Govindaraj ◽  
S. Rajagopan
Keyword(s):  
Electrical Properties ◽  
Molar Ratios ◽  
Nasicon Type

Structural, optical, magnetic, and electrical properties of nanospinels containing different molar ratios of cobalt and aluminum ions

Ionics ◽  
2017 ◽  
Vol 23 (9) ◽  
pp. 2417-2427 ◽  
Author(s):  
Emad M. Masoud ◽  
A.-A. El-Bellihi ◽  
W. A. Bayoumy ◽  
Eman S. Abdelazeem
Keyword(s):  
Electrical Properties ◽  
Molar Ratios ◽  
Aluminum Ions ◽  
Magnetic And Electrical Properties

Synthesis and electrical properties of CuBr2 complexes with 1,10-phenanthroline monohydrate

2008 ◽  
Vol 62 (3) ◽  
Author(s):  
Sülin Taşcıoǧlu ◽  
Esra Kakı ◽  
Mehmet Arı
Keyword(s):  
Electrical Properties ◽  
Electronic Spectroscopy ◽  
Ammonia Solution ◽  
Complex Ii ◽  
Molar Ratios ◽  
Trigonal Bipyramidal ◽  
Structural And Electrical Properties ◽  
Distorted Trigonal Bipyramidal Coordination ◽  
Phenanthroline Monohydrate ◽  
Hydrogen Bondings

AbstractUsing 1,10-phenanthroline monohydrate and CuBr2 in molar ratios of 1:1 and 2:1, in CH3OH/H2O (ϕr = 1:1), the complexes [(phen)CuBr2]2, (I), and {[(phen)2CuBr]Br·H2O}, (II), have been prepared. The hydrogen bondings and aqua bridges between coordinated and noncoordinated bromides of II have been observed by XRD. Complex II has a triclinic crystal structure with distorted trigonal bipyramidal coordination geometry. Possibilities of ligand exchange with hydroxide or ammonia have been examined in both complexes. While the mononuclear complex II is stable in a refluxed ammonia solution and the complex {[phen)2CuBr]Br·3H2O}, (IV), trihydrate of II, is obtained; the binuclear complex I reacts with the ammonia solution to replace one of its bromides in the subunits with hydroxide to give {[(phen)2Cu2Br2(OH)2]·4H2O}, (III). Structural and electrical properties of the complexes have been investigated by elemental analysis, vibrational and electronic spectroscopy, mass spectrometry, TGA, XRD and the four-point probe method. The temperature coefficients of resistivity and the activation energies of the complexes have also been obtained. All complexes behave as intrinsic semiconductor in the temperature range of 310–440 K.

Spark plasma versus conventional sintering in the electrical properties of Nasicon-type materials

2015 ◽  
Vol 651 ◽  
pp. 636-642 ◽  
Author(s):  
M. Pérez-Estébanez ◽  
J. Isasi-Marín ◽  
A. Rivera-Calzada ◽  
C. León ◽  
M. Nygren
Keyword(s):  
Electrical Properties ◽  
Nasicon Type ◽  
Conventional Sintering ◽  
Spark Plasma

Electrical Properties of Mn-Co-Ni Oxides Prepared at Low Temperatures

2007 ◽  
Vol 29-30 ◽  
pp. 359-362 ◽  
Author(s):  
T. Yokoyama ◽  
Takeshi Meguro ◽  
S. Okazaki ◽  
H. Fujikawa ◽  
T. Ishikawa ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Electrical Resistance ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
B Value ◽  
Spinel Oxide ◽  
Practical Application ◽  
Spinel Type ◽  
Molar Ratios ◽  
Increasing Temperature

Changes in crystal phase and electrical properties of oxides composed of Mn, Co, and Ni with the molar ratios of 5:2:1 and 3:3:1 were investigated. Starting oxides were fired from 250°C to 800°C, then maintained at prescribed temperatures for 3 h in air. In the 5:2:1 specimen, a monophase consisting of a cubic spinel oxide that is important to electrical conductivity was obtained at firing temperature of 800°C. In the 3:3:1 specimen, the monophase was obtained at temperatures ranging from 600°C to 800°C. Electrical resistance decreased exponentially with increasing temperature for all specimens fired at temperatures ranging from 250°C to 800°C, indicating that the oxides have intrinsic thermistor characteristics with negative temperature coefficient (NTC). The temperature dependence of the thermistor constant (B value) necessary for practical application was considered to be related to the existence ratio of cubic spinel-type and ilmenite-type structures and the lattice constant of the cubic spinel-type structure. The electrical conduction was stabilized by annealing at prescribed temperatures for more than 720 minutes.

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