SEMICONDUCTOR BEHAVIOR OF 2, 5-AROMATIC DISUBSTITUTED PYROLLES, AN EXPERIMENTAL AND THEORETICAL STUDY

2012 ◽  
Vol 1483 ◽  
Author(s):  
L. Fomina ◽  
C. Y. León Valdivieso ◽  
G. Zaragoza Galán ◽  
M. Bizarro ◽  
I. P. Zaragoza ◽  
...  
Keyword(s):  
Thin Films ◽  
Nitrogen Atom ◽  
Theoretical Study ◽  
Theoretical Calculations ◽  
Electrical Characterization ◽  
Semiconductor Behavior ◽  
Substituted Pyrroles ◽  
Nitro Benzene

ABSTRACTTheoretical calculations were performed on 2, 5-aromatic substituted pyrroles which have a nitro-benzene or a cyano-benzene link to the nitrogen atom of the pyrrol fragment. The molecules manifested interesting semiconductor behavior that was confirmed when thin films were prepared and their corresponding electrical characterization undertaken. The reason for this behavior is discussed, with reference to the electron withdrawing feature of the substituents in the benzene chain.

scholarly journals Ag2O versus Cu2O in the Catalytic Isomerization of Coordinated Diaminocarbenes to Formamidines: A Theoretical Study

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 491
Author(s):  
Juan F. Van der Maelen ◽  
Javier Ruiz
Keyword(s):  
Reaction Mechanism ◽  
Nitrogen Atom ◽  
Carbon Atom ◽  
Transition State ◽  
Theoretical Study ◽  
Theoretical Calculations ◽  
Experimental Results ◽  
Similar Reaction ◽  
Isomerization Process ◽  
Catalytic Isomerization

DFT theoretical calculations for the Ag2O-induced isomerization process of diaminocarbenes to formamidines, coordinated to Mn(I), have been carried out. The reaction mechanism found involves metalation of an N-H residue of the carbene ligand by the catalyst Ag2O and the formation of a key transition state showing a μ-η2:η2 coordination of the formamidinyl ligand between manganese and silver, which allows a translocation process of Mn(I) and silver(I) ions between the carbene carbon atom and the nitrogen atom, before the formation of the formamidine ligand is completed. Calculations carried out using Cu2O as a catalyst instead of Ag2O show a similar reaction mechanism that is thermodynamically possible, but highly unfavorable kinetically and very unlikely to be observed, which fully agrees with experimental results.

Microstructural and Electrical Characterization of Barium Strontium Titanatebased Solid Solution Thin Films Deposited on Ceramic Substrates by Pulsed Laser Deposition

2002 ◽  
Vol 720 ◽  
Author(s):  
Costas G. Fountzoulas ◽  
Daniel M. Potrepka ◽  
Steven C. Tidrow
Keyword(s):  
Thin Films ◽  
Dielectric Constant ◽  
Pulsed Laser Deposition ◽  
Pulsed Laser ◽  
Electrical Characterization ◽  
Field Variable ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
Ceramic Substrates ◽  
Nominal Thickness

AbstractFerroelectrics are multicomponent materials with a wealth of interesting and useful properties, such as piezoelectricity. The dielectric constant of the BSTO ferroelectrics can be changed by applying an electric field. Variable dielectric constant results in a change in phase velocity in the device allowing it to be tuned in real time for a particular application. The microstructure of the film influences the electronic properties which in turn influences the performance of the film. Ba0.6Sr0.4Ti1-y(A 3+, B5+)yO3 thin films, of nominal thickness of 0.65 μm, were synthesized initially at substrate temperatures of 400°C, and subsequently annealed to 750°C, on LaAlO3 (100) substrates, previously coated with LaSrCoO conductive buffer layer, using the pulsed laser deposition technique. The microstructural and physical characteristics of the postannealed thin films have been studied using x-ray diffraction, scanning electron microscopy, and nano indentation and are reported. Results of capacitance measurements are used to obtain dielectric constant and tunability in the paraelectric (T>Tc) regime.

Vapor Deposition Polymerization and Electrical Characterization of TPD Thin Films

2011 ◽  
Vol E94-C (2) ◽  
pp. 157-163 ◽  
Author(s):  
Masakazu MUROYAMA ◽  
Ayako TAJIRI ◽  
Kyoko ICHIDA ◽  
Seiji YOKOKURA ◽  
Kuniaki TANAKA ◽  
...  
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Electrical Characterization

DIRECT GROWTH OF EPITAXIAL La0.67Ca0.33MnO3 - δ THIN FILMS

2002 ◽  
Vol 09 (05n06) ◽  
pp. 1611-1615 ◽  
Author(s):  
G. CAMPILLO ◽  
L. F. CASTRO ◽  
P. VIVAS ◽  
E. BACA ◽  
P. PRIETO ◽  
...  
Keyword(s):  
Thin Films ◽  
Substrate Surface ◽  
Electrical Characterization ◽  
Annealing Treatment ◽  
Pure Oxygen ◽  
X Ray Diffraction ◽  
Atomic Force ◽  
Transmission Electron ◽  
Afm Analysis ◽  
Direct Growth

La 0.67 Ca 0.33 MnO 3 - δ thin films were deposited using a high-pressure dc-sputtering process. Pure oxygen at a pressure of 3.8 mbar was used as sputtering gas. The films were grown on (001) LaAlO 3 and (001) SrTiO 3 substrates at heater temperature of 850° without any annealing treatment. The formation of highly a-axis-oriented films with sharp interface with substrate surface is demonstrated by X-ray diffraction, transmission electron microscope (TEM), and atomic force microscope (AFM) analysis. Electrical characterization revealed a metal–insulator transition at T MI = 276 K, and magnetic characterization showed good magnetic properties with a PM–FM transition at TC ≈ 262 K.

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