Enhanced X‐Ray Photoelectric Yields from Metal‐Insulator Layers

1970 ◽  
Vol 41 (2) ◽  
pp. 815-816
Author(s):  
John E. Jacobs ◽  
Michael G. Kovac
Keyword(s):  
Metal Insulator ◽  
X Ray ◽  
Insulator Layers

High Quality GaAs Mis Diodes With Very Low Surface State Density

1990 ◽  
Vol 209 ◽  
Author(s):  
Yoshihisa Fujisaki ◽  
Sumiko Sakai ◽  
Saburo Ataka ◽  
Kenji Shibata
Keyword(s):  
Chemical Vapor Deposition ◽  
Density Of States ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Chemical Vapor ◽  
State Density ◽  
High Quality ◽  
Metal Insulator ◽  
X Ray ◽  
Mis Devices

ABSTRACTHigh quality GaAs/SiO2 MIS( Metal Insulator Semiconductor ) diodes were fabricated using (NH4)2S treatment and photo-assisted CVD( Chemical Vapor Deposition ). The density of states at the GaAs and SiO2 interface is the order of 1011 cm-2eV-1 throughout the forbidden energy range, which is smaller by the order of two than that of the MIS devices made by the conventional CVD process. The mechanism attributable to the interface improvement was investigated through XPS( X-ray Photoelectron Spectroscopy ) analyses.

scholarly journals Synthesis of Tungsten-Doped Vanadium Dioxide Using a Modified Polyol Method Involving 1-Dodecanol

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5384
Author(s):  
Yonghyun Lee ◽  
Sang Won Jung ◽  
Sang Hwi Park ◽  
Jung Whan Yoo ◽  
Juhyun Park
Keyword(s):  
Linear Growth ◽  
Mixing Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Metal Insulator ◽  
X Ray ◽  
Mixing Ratios ◽  
The Difference ◽  
Modified Polyol Method ◽  
Optimal Mixing

The doping of tungsten into VO2 (M) via a polyol process that is based on oligomerization of ammonium metavanadate and ethylene glycol (EG) to synthesize a vanadyl ethylene glycolate (VEG) followed by postcalcination was carried out by simply adding 1-dodecanol and the tungsten source tungstenoxytetrachloride (WOCl4). Tungsten-doped VEGs (W-VEGs) and their calcinated compounds (WxVO2) were prepared with varying mixing ratios of EG to 1-dodecanol and WOCl4 concentrations. Characterizations of W-VEGs by powder X-ray diffraction, differential scanning calorimetry, scanning electron microscopy, and infrared and transmittance spectroscopy showed that tungsten elements were successfully doped into WxVO2, thereby decreasing the metal-insulator transition temperature from 68 down to 51 °C. Our results suggested that WOCl4 variously combined with 1-dodecanol might interrupt the linear growth of W-VEGs, but that such an interruption might be alleviated at the optimal 1:1 mixing ratio of EG to 1-dodecanol, resulting in the successful W doping. The difference in the solar modulations of a W0.0207VO2 dispersion measured at 20 and 70 °C was increased to 21.8% while that of a pure VO2 dispersion was 2.5%. It was suggested that WOCl4 coupled with both EG and 1-dodecanol at an optimal mixing ratio could improve the formation of W-VEG and WxVO2 and that the bulky dodecyl chains might act as defects to decrease crystallinity.

scholarly journals Effects of strain on La0.67-x Prx Ca0.33 MnO3, LaMn1-x Cox O3 and LaMn1-x Nix O3 magnetite samples

DYNA ◽  
2019 ◽  
Vol 86 (211) ◽  
pp. 278-287
Author(s):  
Javier Alberto Olarte Torres ◽  
María Cristina Cifuentes Arcila ◽  
Harvey Andrés Suárez Moreno
Keyword(s):  
Compressive Strength ◽  
Magnetic Susceptibility ◽  
Sol Gel ◽  
Morphological Characterization ◽  
Electric Resistivity ◽  
The Other ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
X Ray

This paper presents the results obtained from the synthesis and morphological characterization of different magnetite samples:  La0.67-x Prx Ca0.33 MnO3.LaMn1-x Cox O3 and LaMn1-x Nix O3 at 0.13 ≤ 𝑥𝑥 ≤ 0.67 produced by a solid-state reaction mechanism and 𝐿𝐿𝐿𝐿𝑀𝑀𝑀𝑀1−𝑥𝑥(𝐶𝐶𝐶𝐶/𝑁𝑁𝑁𝑁)𝑥𝑥𝑂𝑂3 at 0.0 ≤ 𝑥𝑥 ≤ 0.5 produced by the sol-gel method. These samples were characterized using X-ray diffraction spectroscopy and by measuring electric resistivity and magnetic susceptibility which were carried out as a function of temperature. Notably, the effects of strain and compressive strength on the lattices of magnetite samples were highly dependent on the concentration of 𝑃𝑃𝑟𝑟, 𝐶𝐶𝐶𝐶, and 𝑁𝑁𝑁𝑁. Moreover, the transition temperatures of metal-insulator and ferromagnetic-paramagnetic phases also largely depend on these strength effects, e.g., at higher concentrations of 𝑃𝑃𝑟𝑟, effects of increased strain strength were observed, relocating the shifts of ferromagnetic-paramagnetic transitions to lower temperatures. On the other hand, effects of increased compressive strength were observed at higher concentrations of 𝑁𝑁𝑁𝑁 and 𝐶𝐶𝐶𝐶, relocating the shifts of ferromagnetic-paramagnetic and metal-insulator transitions to higher temperatures.

scholarly journals RNiO3perovskites (R=Pr,Nd): Nickel valence and the metal-insulator transition investigated by x-ray-absorption spectroscopy

1992 ◽  
Vol 46 (23) ◽  
pp. 14975-14984 ◽  
Author(s):  
M. Medarde ◽  
A. Fontaine ◽  
J. L. García-Muñoz ◽  
J. Rodríguez-Carvajal ◽  
M. de Santis ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Insulator Transition ◽  
Metal Insulator Transition ◽  
Metal Insulator ◽  
X Ray ◽  
X Ray Absorption

Magnetic Properties of Hole-Doped Pyrochlore Iridate (Y1-x-yCuxCay)2Ir2O7

2019 ◽  
Vol 966 ◽  
pp. 269-276
Author(s):  
Julia Angel ◽  
Retno Asih ◽  
Hironori Nomura ◽  
Tomoya Taniguchi ◽  
Kazuyuki Matsuhira ◽  
...  
Keyword(s):  
Density Functional ◽  
Muon Spin ◽  
Quantum Critical Point ◽  
Magnetic Ordering ◽  
Photoemission Spectroscopy ◽  
Metal Insulator Transition ◽  
Functional Theory ◽  
Metal Insulator ◽  
X Ray ◽  
Electronic Ground

We report the results of studies on the electronic state of the hole-doped Y-based pyrochlore iridate, (Y1-x-yCuxCay)2Ir2O7. We carried out the resistivity, Muon Spin Relaxation (μSR), X-ray Photoemission Spectroscopy (XPS) measurements and Density Functional Theory (DFT) calculations on the non-doped (x=y=0) and doped (x=0.05, y=0.15) systems. We found in the non-doped system that the magnetic ordering of Ir spins which was accompanied by the metal-insulator transition (MIT) occurred at around 157 K and disappeared in the doped system in which MIT seems to disappear or smeared out. We suggest from the current study that a quantum critical point which shows a change in the electronic ground state from insulating to metallic to exist between those two systems.

MAGNETIC AND TRANSPORT PROPERTIES OFPr0.7Sr0.3MnO3/La0.5Ca0.5MnO3/Pr0.7Sr0.3MnO3TRILAYERS

2012 ◽  
Vol 26 (23) ◽  
pp. 1250132 ◽  
Author(s):  
H. O. WANG ◽  
P. DAI ◽  
H. LIU ◽  
W. S. TAN ◽  
F. XU ◽  
...  
Keyword(s):  
Transport Properties ◽  
Exchange Bias ◽  
Volume Fraction ◽  
Magnetic Phase ◽  
X Ray Diffraction ◽  
High Crystalline Quality ◽  
Metal Insulator ◽  
X Ray ◽  
Diffraction Patterns ◽  
Oriented Single Crystal

All-manganites Pr0.7Sr0.3MnO3/ La0.5Ca0.5MnO3/ Pr0.7Sr0.3MnO3(PSMO/LCMO/PSMO) trilayers were deposited on (001)-oriented single crystal MgO by pulsed laser deposition. The thickness of both PSMO layers was 36 nm while the thickness of LCMO layer varied from 6 to 36 nm. High resolution X-ray diffraction patterns indicated that trilayers were well (001)-oriented grown with high crystalline quality, and that PSMO layers were fully-strain-relaxed while LCMO spacer was partially strained. Studies on transport and magnetic properties of trilayers indicated that metal-insulator transition temperature TMIincreased from 200 K to 260 K and the saturation magnetization was suppressed with decreasing thickness of LCMO spacer from 36 to 6 nm. Transport properties of trilayers are associated with enhancement of volume fraction of ferromagnetic clusters in charge ordered and magnetic phase separated LCMO spacer. Interestingly, exchange bias (EB) was not observed in PSMO/LCMO/PSMO trilayers. It was believed that preferential distribution of metallic ferromagnetic clusters in LCMO layer may result in disappearance of EB.

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