A study of high-purity CdxSe1−x vacuum-deposited thin films

1991 ◽  
Vol 69 (2) ◽  
pp. 124-130 ◽  
Author(s):  
E. Dufresne ◽  
D. E. Brodie
Keyword(s):  
Thin Films ◽  
Electrical Transport ◽  
Amorphous Materials ◽  
Room Temperature ◽  
Electrical Transport Properties ◽  
Amorphous Films ◽  
Electrical And Optical Properties ◽  
Crystallite Sizes ◽  
Excess Component ◽  
Pure Cdse

Pure CdSe films were vacuum deposited onto liquid-nitrogen-cooled substrates using a doubly baffled source in an attempt to prepare and study amorphous CdSe. The deposition of stable stoichiometric amorphous pure films was not verified since the films were always polycrystalline when analyzed at room temperature. CdSe appears to be different from some other II– VI compounds that can be prepared as pure stoichiometric amorphous materials and can be studied at a temperature up to 400 K. Pure nonstoichiometric films were also prepared using a second source to supply the excess component. Amorphous Se-rich films could only be produced for samples with at least 59 at.% Se. For Cd-rich films, the excess Cd agglomerates and the CdSe crystallite sizes are smaller than those observed in stoichiometric films. The electrical and optical properties scale as a function of the Cd content and the films become metallike as the Cd content increases through 60 at.%. The electrical transport properties are very different for polycrystalline films, depending on whether the CdSe is deposited on a hot substrate, or on a cold substrate and annealed to the same high temperature. We show that impure amorphous films of CdSe can be deposited if the system's background pressure is high.

Microstructures, Electrical and Magnetic Properties of Zn Doped Co Nanoferrites

2012 ◽  
Vol 510-511 ◽  
pp. 221-226 ◽  
Author(s):  
M. Akram ◽  
M. Anis-ur-Rehman ◽  
M. Mubeen ◽  
M. Ali
Keyword(s):  
Magnetic Properties ◽  
Electrical Transport ◽  
Room Temperature ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Electrical Transport Properties ◽  
X Ray ◽  
Electrical And Magnetic Properties ◽  
Crystallite Sizes ◽  
Co Precipitation

Non toxicity, bio compatibility and nanometer sizes regime which is comparable to the size of a cell, makes nanocrystalline Co ferrites particles very proficient. In the present research Zn doped cobalt ferrites were prepared by the chemical co-precipitation method and characterized by X-ray diffraction (XRD) at room temperature for structural analysis. X-ray diffraction patterns confirmed the FCC spinel structure of synthesized particles. Crystallite sizes were calculated from the most intense peak (311) using the Debye-Scherrer formula. The obtained crystallite sizes were in nanometer range for all the samples synthesized at reaction temperature of 70°C. Then samples were sintered at 550°C for 2 hours, characterized again by X-ray diffraction at room temperature. The crystallite sizes and lattice constants for all the samples were calculated again from the data obtained by XRD. DC electrical resistivity and AC electrical transport properties were analyzed. The magnetic properties such as coercivity (Hc) and remanence (Mr) of Co1-xZnxFe2O4for x = 0.0, 0.2, 0.4 were measured at room temperature by vibrating sample magnetometer. Coercivity and remanence were found maximum with minimum value of Zn in Co1-xZnxFe2O4.Observed structural and conduction properties of synthesized nanomaterials were correlated.

Effects of Deposition Temperature and Film Thickness on the Structural, Electrical, and Optical Properties of Germanium Thin Films

2002 ◽  
Vol 715 ◽  
Author(s):  
William B. Jordan ◽  
Sigurd Wagner
Keyword(s):  
Thin Films ◽  
High Temperature ◽  
Film Thickness ◽  
Vapor Deposition ◽  
Electrical Transport ◽  
Deposition Temperature ◽  
High Mobility ◽  
Chemical Vapor ◽  
Electrical Transport Properties ◽  
Electrical And Optical Properties

AbstractGermanium films deposited on glass by plasma-enhanced chemical vapor deposition from germane and hydrogen grow in the structure succession of amorphous-nanocrystallineamorphous-nanocrystalline as the substrate temperature is raised from 30°C to 310°C. We ascribe the phase formation, from low to high temperature, to a sequence of low to high mobility of Ge growth species on a surface that is hydrogenated at low temperature but not hydrogenated at high temperature. We report some structural, optical, and electrical transport properties of Ge films as a function of deposition temperature and film thickness.

Interface motion during recrystallization of amorphous NiSi2

1990 ◽  
Vol 48 (4) ◽  
pp. 524-525
Author(s):  
J. L. Batstone ◽  
D.A. Smith
Keyword(s):  
Thin Films ◽  
Room Temperature ◽  
Amorphous Film ◽  
Nucleation And Growth ◽  
Recrystallization Process ◽  
Amorphous Films ◽  
Interface Motion ◽  
Si Substrates ◽  
Spherical Caps ◽  
Crystal Interfaces

Recrystallization of amorphous NiSi2 involves nucleation and growth processes which can be studied dynamically in the electron microscope. Previous studies have shown thatCoSi2 recrystallises by nucleating spherical caps which then grow with a constant radial velocity. Coalescence results in the formation of hyperbolic grain boundaries. Nucleation of the isostructural NiSi2 results in small, approximately round grains with very rough amorphous/crystal interfaces. In this paper we show that the morphology of the rccrystallizcd film is dramatically affected by variations in the stoichiometry of the amorphous film.Thin films of NiSi2 were prepared by c-bcam deposition of Ni and Si onto Si3N4, windows supported by Si substrates at room temperature. The base pressure prior to deposition was 6 × 107 torr. In order to investigate the effect of stoichiomctry on the recrystallization process, the Ni/Si ratio was varied in the range NiSi1.8-2.4. The composition of the amorphous films was determined by Rutherford Backscattering.

scholarly journals Electrical transport properties and Kondo effect in La1−xPrxNiO3−δ thin films

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Van Hien-Hoang ◽  
Nak-Kwan Chung ◽  
Heon-Jung Kim
Keyword(s):  
Thin Films ◽  
Electrical Transport ◽  
Kondo Effect ◽  
Magnetic Moments ◽  
Structural Disorder ◽  
Strongly Correlated ◽  
Electrical Transport Properties ◽  
Strongly Correlated Electron ◽  
Correlated Electron Systems ◽  
Correlated Electron

AbstractThe Kondo effect has been a topic of intense study because of its significant contribution to the development of theories and understanding of strongly correlated electron systems. In this work, we show that the Kondo effect is at work in La1−xPrxNiO3−δ (0 ≤ x ≤ 0.6) thin films. At low temperatures, the local magnetic moments of the 3d eg electrons in Ni2+, which form because of oxygen vacancies, interact strongly with itinerant electrons, giving rise to an upturn in resistivity with x ≥ 0.2. Observation of negative magnetoresistance, described by the Khosla and Fisher model, further supports the Kondo picture. This case represents a rare example of the Kondo effect, where Ni2+ acts as an impurity in the background of Ni3+. We suggest that when Ni2+ does not participate in the regular lattice, it provides the local magnetic moments needed to scatter the conduction electrons in the Kondo effect. These results offer insights into emergent transport behaviors in metallic nickelates with mixed Ni3+ and Ni2+ ions, as well as structural disorder.

Buffer Layer Thickness and the Properties of InN Thin Films on AIN- Seeded (00.1) Sapphire And (111) Silicon

1994 ◽  
Vol 339 ◽  
Author(s):  
T. J. Kistenmacher ◽  
S. A. Ecelberger ◽  
W. A. Bryden
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Layer Thickness ◽  
Electrical Transport ◽  
Lattice Mismatch ◽  
Electrical Mobility ◽  
Seeded Growth ◽  
Electrical Transport Properties ◽  
Buffer Layer Thickness ◽  
Homogeneous Strain

ABSTRACTIntroduction of a buffer layer to facilitate heteroepitaxy in thin films of the Group IIIA nitrides has had a tremendous impact on growth morphology and electrical transport. While AIN- and self-seeded growth of GaN has captured the majority of attention, the use of AIN-buffered substrates for InN thin films has also had considerable success. Herein, the properties of InN thin films grown by reactive magnetron sputtering on AIN-buffered (00.1) sapphire and (111) silicon are presented and, in particular, the evolution of the structural and electrical transport properties as a function of buffer layer sputter time (corresponding to thicknesses from ∼50Å to ∼0.64 μm) described. Pertinent results include: (a) for the InN overlayer, structural coherence and homogeneous strain normal to the (00.1) growth plane are highly dependent on the thickness of the AIN-buffer layer; (b) the homogeneous strain in the AIN-buffer layer is virtually nonexistent from a thickness of 200Å (where a significant X-ray intensity for (00.2)AIN is observed); and (c) the n-type electrical mobility for films on AIN-nucleated (00.1) sapphire is independent of AIN-buffer layer thickness, owing to divergent variations in carrier concentration and film resistivity. These effects are in the main interpreted as arising from a competition between the lattice mismatch of the InN overlayer with the substrate and with the AIN-buffer layer.

scholarly journals Resistive switching in diamondoid thin films

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
A. Jantayod ◽  
D. Doonyapisut ◽  
T. Eknapakul ◽  
M. F. Smith ◽  
W. Meevasana
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Transport Properties ◽  
Resistive Switching ◽  
Electrical Transport ◽  
Hysteresis Curve ◽  
Applied Potential ◽  
Electrical Transport Properties ◽  
Non Volatile Memory ◽  
Memory Applications

Abstract The electrical transport properties of a thin film of the diamondoid adamantane, deposited on an Au/W substrate, were investigated experimentally. The current I, in applied potential V, from the admantane-thiol/metal heterstructure to a wire lead on its surface exhibited non-symmetric (diode-like) characteristics and a signature of resistive switching (RS), an effect that is valuable to non-volatile memory applications. I(V) follows a hysteresis curve that passes twice through $$I(0)=0$$ I ( 0 ) = 0 linearly, indicating RS between two states with significantly different conductances, possibly due to an exotic mechanism.

scholarly journals Impact of defects on the structural and electrical transport properties of Sb2Te3 thin films by SHI irradiation

2021 ◽  
pp. 100113
Author(s):  
Jyoti Yadav ◽  
Rini Singh ◽  
M.D. Anoop ◽  
Nisha Yadav ◽  
N. Srinivasa Rao ◽  
...  
Keyword(s):  
Thin Films ◽  
Transport Properties ◽  
Electrical Transport ◽  
Electrical Transport Properties ◽  
Shi Irradiation

Temperature dependence of electrical transport properties of La4BaCu5−xCoxO13+δconducting oxide thin films

2016 ◽  
Vol 55 (4S) ◽  
pp. 04EJ08
Author(s):  
Akihiro Tsuruta ◽  
Yusuke Tsujioka ◽  
Yutaka Yoshida ◽  
Ichiro Terasaki ◽  
Norimitsu Murayama ◽  
...  
Keyword(s):  
Thin Films ◽  
Temperature Dependence ◽  
Transport Properties ◽  
Electrical Transport ◽  
Oxide Thin Films ◽  
Electrical Transport Properties
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