V2O5 Thin Films as Nitrogen Dioxide Sensors †

Vanadium pentoxide thin films were deposited onto insulating support by means of rf reactive sputtering from a metallic vanadium target. Argon-oxygen gas mixtures of different compositions controlled by the flow rates were used for sputtering. X-ray diffraction at glancing incidence (GIXD) and Scanning Electronic Microscopy (SEM) were used for structural and phase characterization. Thickness of the films was determined by the profilometry. It has been confirmed by GIXD that the deposited films are composed of V2O5 phase. The gas sensing properties of V2O5 thin films were investigated at temperatures from range 410–617 K upon NO2 gas of 4–20 ppm. The investigated material exhibited good response and reversibility towards nitrogen dioxide. The effect of metal-insulator transition (MIT) on sensor performance has been observed and discussed for the first time. It was found that a considerable increase of the sensor sensitivity occured above 545 K, which is related to postulated metal-insulator transition.

Download Full-text

V2O5 Thin Films as Nitrogen Dioxide Sensors

Proceedings ◽

10.3390/proceedings2130759 ◽

2018 ◽

Vol 2 (13) ◽

pp. 759

Author(s):

Krystyna Schneider ◽

Wojciech Maziarz

Keyword(s):

Thin Films ◽

Nitrogen Dioxide ◽

Gas Sensing ◽

Optical Transmittance ◽

Fused Silica ◽

X Ray Diffraction ◽

Gas Sensing Properties ◽

Oxygen Gas ◽

V2o5 Thin Films ◽

Phase Characterization

V2O5 thin films were deposited onto insulating support (either fused silica or alumina) by means of rf reactive sputtering from a metallic vanadium target. Argon-oxygen gas mixtures of different compositions controlled by the flow rates were used for sputtering. X-ray diffraction at glancing incidence (GIXD) and Scanning Electronic Microscopy (SEM) were used for structural and phase characterization. Optical transmittance and reflectance spectra were recorded with a Lambda 19 Perkin-Elmer double spectrophotometer. Thickness of the films was determined from the profilometry. It has been confirmed by GIXD that the deposited films are composed of V2O5 phase. The estimated optical band gap was ca. 2.5 eV. The gas sensing properties of V2O5 thin films were investigated at RT-690 K towards NO2 gas of 0–20 ppm. The results indicated that material exhibited good response and reversibility towards nitrogen dioxide.

Download Full-text

X-ray diffraction investigation of the relationship between strains and metal-insulator transition in NdNiO3 thin films

Crystal Engineering ◽

10.1016/s1463-0184(02)00043-6 ◽

2002 ◽

Vol 5 (3-4) ◽

pp. 317-325 ◽

Cited By ~ 11

Author(s):

P. Goudeau ◽

P. Laffez ◽

M. Zaghrioui ◽

E. Elkaim ◽

P. Ruello

Keyword(s):

Thin Films ◽

Insulator Transition ◽

X Ray Diffraction ◽

Metal Insulator Transition ◽

Metal Insulator ◽

X Ray ◽

The Relationship

Download Full-text

Giant Magnetoresistance Phenomenon in Laser Ablated La0.6y0.07ca0.33mnox Thin Films

MRS Proceedings ◽

10.1557/proc-397-241 ◽

1995 ◽

Vol 397 ◽

Cited By ~ 2

Author(s):

Dhananjay Kumar ◽

R. Kalyanaraman ◽

J. Narayan ◽

David K. Christen

Keyword(s):

Thin Films ◽

Giant Magnetoresistance ◽

Lattice Parameter ◽

Insulator Transition ◽

X Ray Diffraction ◽

Metal Insulator Transition ◽

Metal Insulator ◽

Spin Dependent Scattering ◽

Resistance Peak

ABSTRACTMicrostructural and magnetoresistance properties of La0.6Y0.07Ca0.33MnOx (Y-doped LCMO) thin films grown in-situ by pulsed laser ablation have been studied. Transmission election microscopy and x-ray diffraction measurements have shown that the Y-doped LCMO thin films grow epitaxially on (100) LaAl03 substrates and are cubic with a lattice parameter of 3.849 ?. The as-deposited films exhibited a metal-insulator transition at 130 K and a giant magnetoresistance (GMR) at 125 K with a MR ratio (dR/RH) of 1500% in the presence of a magnetic field of 6 Tesla. Such a colossal value of MR ratio for as-deposited Y-doped LCMO films is quite promising keeping in view the fact that these films were unannealed and not optimized. We ascribe this magnetoresistance to spin-dependent electron scattering coupled with the presence of intervening O2. ions across Mn3+ and Mn4+ with suppressed separation between Mn-O layers caused by smaller sized Y-dopant. The effect of annealing on the positive-shift of metal-insulator transition temperature and the improvement in GMR ratio has also been discussed. We also report a non-ohmic response in the Y-doped LCMO films which is observed only in the region of the resistance peak and lends support to a conduction mechanism in these materials based on spin-dependent scattering of electrons.

Download Full-text

Conductive AFM of Percolative Metal-Insulator Transition in Polycrystalline (La[sub 0.91]Sr[sub 0.09])MnO[sub 3] Thin Films Deposited on Si Substrate

Electrochemical and Solid-State Letters ◽

10.1149/1.2200067 ◽

2006 ◽

Vol 9 (7) ◽

pp. J27 ◽

Cited By ~ 4

Author(s):

Yen-Hua Chen ◽

Shu-Te Ho ◽

Tai-Bor Wu

Keyword(s):

Thin Films ◽

Insulator Transition ◽

Si Substrate ◽

Metal Insulator Transition ◽

Metal Insulator ◽

Conductive Afm

Download Full-text

Study of Transport Phenomenon in Amorphous RexSi1 – x Thin Films on the Both Sides of the Metal–Insulator Transition at Very Low Temperatures

Physics of the Solid State ◽

10.1134/s1063783420120215 ◽

2020 ◽

Vol 62 (12) ◽

pp. 2445-2451

Author(s):

A. El Oujdi ◽

S. Dlimi ◽

A. Echchelh ◽

A. El Kaaouachi

Keyword(s):

Thin Films ◽

Transport Phenomenon ◽

Low Temperatures ◽

Insulator Transition ◽

Metal Insulator Transition ◽

Metal Insulator

Download Full-text

Bandwidth controlled Metal‐Insulator Transition in Au‐ VO 2 Nanocomposite Thin Films

Journal of the American Ceramic Society ◽

10.1111/jace.16166 ◽

2018 ◽

Cited By ~ 1

Author(s):

Guangsheng Fu ◽

Xingkun Ning ◽

Mingjing Chen ◽

Shufang Wang ◽

Peng Liu ◽

...

Keyword(s):

Thin Films ◽

Insulator Transition ◽

Metal Insulator Transition ◽

Metal Insulator ◽

Nanocomposite Thin Films

Download Full-text

Study of Microstructural, Electrical and Dielectric Properties of La0.9Pb0.1MnO3 and La0.8Y0.1Pb0.1MnO3 Ceramics

The Journal of Social Sciences Research ◽

10.32861/sr.52.33.44 ◽

2019 ◽

pp. 33-44 ◽

Cited By ~ 1

Keyword(s):

Transition Temperature ◽

Frequency Dispersion ◽

Insulator Transition ◽

X Ray Diffraction ◽

Phonon Modes ◽

Metal Insulator Transition ◽

Metal Insulator ◽

Solid State Route ◽

Distorted Structure ◽

Lower Temperature

The present work studies the microstructural and electrical properties of La0.9Pb0.1MnO3 and La0.8Y0.1Pb0.1MnO3 ceramics synthesized by solid-state route method. Microstructure and elemental analysis of both samples were carried out by field emission scanning electron microscope (FESEM) and energy dispersive spectroscopy (EDS) method, respectively. Phase analysis by X-ray diffraction (XRD) indicated formation of single phase distorted structure. The XRD data were further analyzed by Rietveld refinement technique. Raman analysis reveals that Y atom substitutes La site into the LPMO with shifting of phonon modes. The temperature variation of resistivity of undoped and Y-doped La0.9Pb0.1MnO3 samples have been investigated. The electrical resistivity as a function of temperature showed that all samples undergo an metal-insulator (M-I) transition having a peak at transition temperature TMI. Y-doping increases the resistivity and the metal-insulator transition temperature (TMI) shifts to lower temperature. The temperature-dependent resistivity for temperatures less than metal-insulator transition is explained in terms the quadratic temperature dependence and for T > TMI, thermally activated conduction (TAC) is appropriate. Variation of frequency dispersion in permittivity and loss pattern due to La-site substitution in LPMO was observed in the dielectric response curve.

Download Full-text