Stabilization of the metallic state by electric currents in phase-separated manganite thin films

2007 ◽  
Vol 76 (18) ◽  
Author(s):  
Naoko Takubo ◽  
Kenjiro Miyano
Keyword(s):  
Thin Films ◽  
Metallic State ◽  
Electric Currents

Pseudogap formation in the metallic state of La0.7Sr0.3MnO3 thin films

2008 ◽  
Vol 93 (21) ◽  
pp. 212503 ◽  
Author(s):  
Udai Raj Singh ◽  
Anjan K. Gupta ◽  
Goutam Sheet ◽  
Venkat Chandrasekhar ◽  
H. W. Jang ◽  
...  
Keyword(s):  
Thin Films ◽  
Metallic State

The Transition to the Metallic State in Polycrystallinen-type Doped ZnO Thin Films

2014 ◽  
Vol 640 (6) ◽  
pp. 1054-1062 ◽  
Author(s):  
Alex T. Vai ◽  
Vladimir L. Kuznetsov ◽  
Himanshu Jain ◽  
Daniel Slocombe ◽  
Nazanin Rashidi ◽  
...  
Keyword(s):  
Thin Films ◽  
Zno Thin Films ◽  
Metallic State ◽  
Doped Zno

Exploiting the Metal-Insulator Transition of VO2 Thin Films for Terahertz Wave Modulation and Switching

2015 ◽  
Vol 1805 ◽  
Author(s):  
Md Nadim Ferdous Hoque ◽  
Gulten Karaoglan-Bebek ◽  
Mark Holtz ◽  
Ayrton A. Bernussi ◽  
Zhaoyang Fan
Keyword(s):  
Thin Films ◽  
Charge Density ◽  
Amplitude Modulation ◽  
Modulation Depth ◽  
Insulator Transition ◽  
Thz Radiation ◽  
Metallic State ◽  
Light Modulator ◽  
Metal Insulator Transition ◽  
Metal Insulator

ABSTRACTVO2 is one of the very few natural materials that can be used to modulate terahertz (THz) radiations. A 100-nm thick VO2, when in its metallic phase, has a charge density of more than ∼ 1015 cm-2 which will strongly reflect and absorb the THz radiation; while in its insulator state, the charge density is lowered by several orders of magnitude to be THz transparent. Therefore, exploiting the metal-insulator transition of VO2 is a potential approach to modulate or even switch THz radiation for THz optics. Here we report that VO2 epitaxial thin films on sapphire substrate exhibits 85% amplitude modulation depth in a broad bandwidth, while this value can be improved to 95% when VO2 film is coated on both sides of a substrate. We further demonstrate that with wafer bonding, 4-layered VO2 thin films exhibit a transmittance as low as -20 dB to -30 dB at their metallic state, enough for switching applications. We also report our proof-of-concept demonstration of THz spatial light modulator that exhibits amplitude modulation as large as 96%, -30 dB pixel-to-pixel crosstalk, and a broad THz bandwidth.

scholarly journals Switchable Piezoresistive SmS Thin Films on Large Area

Sensors ◽  
2019 ◽  
Vol 19 (20) ◽  
pp. 4390 ◽  
Author(s):  
Andreas Sousanis ◽  
Dirk Poelman ◽  
Christophe Detavernier ◽  
Philippe F. Smet
Keyword(s):  
Thin Films ◽  
Photoelectron Spectroscopy ◽  
Metallic State ◽  
Large Area ◽  
Thermally Induced ◽  
X Ray ◽  
Piezoresistive Sensors ◽  
Deposition Parameters ◽  
Structural And Electrical Properties ◽  
Samarium Monosulfide

Samarium monosulfide (SmS) is a switchable material, showing a pressure-induced semiconductor to metal transition. As such, it can be used in different applications such as piezoresistive sensors and memory devices. In this work, we present how e-beam sublimation of samarium metal in a reactive atmosphere can be used for the deposition of semiconducting SmS thin films on 150 mm diameter silicon wafers. The deposition parameters influencing the composition and properties of the thin films are evaluated, such as the deposition rate of Sm metal, the substrate temperature and the H2S partial pressure. We then present the changes in the optical, structural and electrical properties of this compound after the pressure-induced switching to the metallic state. The back-switching and stability of SmS thin films are studied as a function of temperature and atmosphere via in-situ X-ray diffraction. The thermally induced back switching initiates at 250 °C, while above 500 °C, Sm2O2S is formed. Lastly, we explore the possibility to determine the valence state of the samarium ions by means of X-ray photoelectron spectroscopy.

Structural and optical properties of MgyNi1–yHx gradient thin films in relation to the as-deposited metallic state

2009 ◽  
Vol 34 (21) ◽  
pp. 8951-8957 ◽  
Author(s):  
R. Gremaud ◽  
J.L.M. van Mechelen ◽  
H. Schreuders ◽  
M. Slaman ◽  
B. Dam ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Metallic State ◽  
Structural And Optical Properties

High Crystalline Cu2O Thin Films Prepared by Electric Current Heating Using Copper Wire

2014 ◽  
Vol 90 ◽  
pp. 66-71
Author(s):  
Tomoichiro Okamoto ◽  
Ko Yamazaki ◽  
Yuichiro Kuroki ◽  
Masasuke Takata
Keyword(s):  
Thin Films ◽  
Oxygen Partial Pressure ◽  
Partial Pressure ◽  
Electric Current ◽  
Atmospheric Pressure ◽  
Copper Wire ◽  
Time Response ◽  
Controlled Atmosphere ◽  
Electric Currents ◽  
Glass Substrates

Cu wires were heated by electric currents to fabricate Cu2O thin films. The films were successfully deposited on glass substrates placed above the wires at air pressures in the range of 100 - 40 Pa. Then the films were annealed in a controlled atmosphere and investigated the crystallinity, morphology and the time response to illumination of the films. After annealing at 800 °C at atmospheric pressure with oxygen partial pressure of 12 Pa, the crystallinity was increased and the time response of photoconduction was successfully improved.

scholarly journals Sensitivity of the superconducting state in thin films

2019 ◽  
Vol 5 (3) ◽  
pp. eaau3826 ◽  
Author(s):  
I. Tamir ◽  
A. Benyamini ◽  
E. J. Telford ◽  
F. Gorniaczyk ◽  
A. Doron ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Low Temperatures ◽  
Superconducting Films ◽  
Theoretical Explanation ◽  
Two Dimensions ◽  
Metallic State ◽  
External Radiation ◽  
External Perturbations ◽  
Extreme Sensitivity

For more than two decades, there have been reports on an unexpected metallic state separating the established superconducting and insulating phases of thin-film superconductors. To date, no theoretical explanation has been able to fully capture the existence of such a state for the large variety of superconductors exhibiting it. Here, we show that for two very different thin-film superconductors, amorphous indium oxide and a single crystal of 2H-NbSe2, this metallic state can be eliminated by adequately filtering external radiation. Our results show that the appearance of temperature-independent, metallic-like transport at low temperatures is sufficiently described by the extreme sensitivity of these superconducting films to external perturbations. We relate this sensitivity to the theoretical observation that, in two dimensions, superconductivity is only marginally stable.

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