scholarly journals Sintering-temperature dependent on the room temperature electrical properties of Sr2FeMoO6

2018 ◽  
Author(s):  
H. Laysandra ◽  
D. Triyono ◽  
R. A. Rafsanjani
2007 ◽  
Vol 997 ◽  
Author(s):  
Robert Mueller ◽  
Joris Billen ◽  
Rik Naulaerts ◽  
Olivier Rouault ◽  
Ludovic Goux ◽  
...  

AbstractCuTCNQ (TCNQ=7,7,8,8-tetracyanoquinodimethane) is a resistive switching charge-transfer complex which can be used for organic nonvolatile memories. In this contribution we report on a thorough investigation of the electrical switching of CuTCNQ memories. Our memories currently achieve an endurance of up to 10000 write/erase cycles with a clear distinction between ON and OFF reading currents. ON and OFF threshold voltages follow a Gaussian distribution. Temperature dependent measurements of CuTCNQ based organic memories show a semiconductor like behavior for the ON state. The retention time of the ON state exceeded 60 hours at room temperature. Electrical switching of CuTCNQ memories in air was virtually not affected by temperatures up to 80°C, but becomes erratic at 120°C. The CuTCNQ material itself already starts to decompose around 200°C in presence of oxygen as shown by thermogravimetric analysis.


2019 ◽  
Vol 93 (3) ◽  
pp. 666-677 ◽  
Author(s):  
Drashti Sanghvi ◽  
Hetal Boricha ◽  
Bharavi Hirpara ◽  
Sapana Solanki ◽  
V. G. Shrimali ◽  
...  

2003 ◽  
Vol 798 ◽  
Author(s):  
D. B. Haddad ◽  
H. Dai ◽  
R. Naik ◽  
C. Morgan ◽  
V. M. Naik ◽  
...  

ABSTRACTThe optical and electrical properties of InN films with different levels of carrier concentrations have been investigated. Hall effect measurements at room temperature show that the InN films are n-type with carrier concentration, ne, ranging from ∼ 7 ×1017 cm-3 to ∼ 3 × 1020 cm-3 and corresponding mobility, //, of ∼ 1300 to 50 cm2V-1S-1. Optical absorption spectra of these films show a bandgap absorption edge ∼ 0.6 eV for the InN sample with the lowest ne, and 1.5 eV for the InN sample with the highest ne. However, after corrections for the degeneracy effects, all samples show an intrinsic Eg ∼ (0.60 ± 0.05) eV. Temperature dependent (5 – 600 K) electrical measurements show that ne is nearly independent of temperature below 300 K, perhaps due to the presence of donor energy levels resonating with the InN conduction band. However, all the samples show an exponential increase in ne above 300 K due to excitation of other shallow donor like sources. Mobility versus temperature graph shows a maximum ∼ 200 K for InN film with ne = 7 × 1017 cm-3 and moves towards lower temperature with increasing ne.


2016 ◽  
Vol 881 ◽  
pp. 123-127 ◽  
Author(s):  
A.C.B. de Oliveira ◽  
D.M.S. Ribeiro ◽  
C.G.P. Moraes ◽  
R.S. Silva ◽  
Nilson Santos Ferreira ◽  
...  

This work presents the synthesis and characterization of NTC ceramic (Negative coefficient Temperature) based on nickel manganite (NiMn2O4) produced by the polymeric precursor method. NiMn2O4 were sintered at 900-1200 °C during 3h to produce the ceramics samples. The effect of sintering temperature on microstructure and electric properties of the NiMn2O4 ceramics was studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and temperature dependent resistance R(T) measurements. The XRD measurement indicated formation of cubic spinel-type structure of NiMn2O4. The crystallite size (as confirmed by XRD) and the particle size (as confirmed by SEM) increased as the sintering temperature increased from around 18nm (900 °C) to 100nm (1200 °C). All samples showed NTC behavior and, among the studied ceramics, that one sintered at 1200 °C showed lower resistivity value (~103Ω.cm) at room temperature.


Author(s):  
Shamima Choudhury ◽  
Shurayya Akter ◽  
MJ Rahman ◽  
AH Bhuiyan ◽  
SN Rahman ◽  
...  

The microstructural and electrical properties of pure and Zirconium (Zr) doped Barium titanate (BT) samples with general formula Ba(Ti1-xZrx)O3 (where x=0.0, 0.1, 0.2 and 0.3), prepared by high temperature solid state reaction at a sintering temperature of 1250° C, were investigated. Dielectric and structural properties of BT ceramics is influenced significantly by small addition of ZrO2. Scanning Electron Microscope (SEM) observations revealed enhanced microstructural uniformity and retarded grain growth with increasing Zr content. The dielectric study with frequency at room temperature in the frequency range 75 kHz to 30 MHz shows that dielectric constant decreases with increasing frequency. The resistivity of the samples shows asymptotic behavior with the variation of frequency and was found to be of the order of ~103 Ω-m. Loss factor of the grown materials decreased with increasing frequency but it became independent at higher frequency range. doi: 10.3329/jbas.v32i2.2434 Journal of Bangladesh Academy of Sciences Vol.32(2) 2008 151-159


2017 ◽  
Vol 6 (2) ◽  
pp. 145 ◽  
Author(s):  
Kh.S. Karimov ◽  
M.H. Sayyad ◽  
M.M. Ahmed ◽  
M.N. Khan ◽  
Z.M. Karieva ◽  
...  

<p>In this study the effect of temperature and humidity on electrical properties of organic orange dye (OD) complex with vinyl-ethynyl-trimethyl-piperidole (VETP) have been examined. Thin films of OD (C<sub>17</sub>H<sub>17</sub>N<sub>5</sub>O<sub>2</sub>) and VETP (C<sub>12</sub>H<sub>19</sub>NO) complex were deposited from 10 wt.% (5 wt.% of each matter) solution in mixture of distilled water (80%) and spirit. The films were grown at room temperature under normal gravity conditions, <em>i.e.</em>, 1 g and in a spin coater at an angular speed of 300 RPM. The Cu/OD-VETP/Cu surface type samples were fabricated and their low frequency (10 Hz) AC electric characteristics were evaluated for the temperature range 30-95 °C at ambient humidity of 45-80%. It was observed that at normal conditions the conductivity of the samples is temperature dependent and shows semi-conductive behavior with activation energy of 0.55 eV. It was found that with increase in humidity the resistance of the samples decreases and at humidity values equal to 60-70% the irreversible transition from semi-conductive to conductive state takes place. It is supposed that in the former state the conductive matrix is formed due to incorporation of the water molecules into OD-VETP complex.</p>


2014 ◽  
Vol 881-883 ◽  
pp. 1031-1034
Author(s):  
Xu Xin Cheng ◽  
Dong Xiang Zhou ◽  
Zhao Xiong Zhao ◽  
Qiu Yun Fu

Positive temperature coefficient of resistivity (PTCR) effect and electrical properties of (Ban-xSmx)TiO3(BSMT ) samples with different Ba-site/Ti-site ratio (n) and various concentration of the donor-doped Sm3+(x) sintered in a reducing atmosphere and reoxidized in air are investigated. The results show that the room temperature resistivity (ρRT) of the semiconducting BSMT ceramics first decreases and then increases with increasing of concentration of the donor-doped Sm3+, especially whenxis 0.005 mol, the ρRTof the BSMT ceramics is the lowest. Moreover, the ρRTof the Ba-excess BSMT (n= 1.01) specimens reoxidized at 800 oC for 1 h after sintering at 1270 °C for 30 min in a reducing atmosphere is lower than the Ti-excess ones (n= 0.99), in addition, the ρRTof the BSMT specimens increases with an increase of both sintering temperature and reoxidized time.


Author(s):  
T.E. Pratt ◽  
R.W. Vook

(111) oriented thin monocrystalline Ni films have been prepared by vacuum evaporation and examined by transmission electron microscopy and electron diffraction. In high vacuum, at room temperature, a layer of NaCl was first evaporated onto a freshly air-cleaved muscovite substrate clamped to a copper block with attached heater and thermocouple. Then, at various substrate temperatures, with other parameters held within a narrow range, Ni was evaporated from a tungsten filament. It had been shown previously that similar procedures would yield monocrystalline films of CU, Ag, and Au.For the films examined with respect to temperature dependent effects, typical deposition parameters were: Ni film thickness, 500-800 A; Ni deposition rate, 10 A/sec.; residual pressure, 10-6 torr; NaCl film thickness, 250 A; and NaCl deposition rate, 10 A/sec. Some additional evaporations involved higher deposition rates and lower film thicknesses.Monocrystalline films were obtained with substrate temperatures above 500° C. Below 450° C, the films were polycrystalline with a strong (111) preferred orientation.


1996 ◽  
Vol 452 ◽  
Author(s):  
N. H. Nickel ◽  
E. A. Schiff

AbstractThe temperature dependence of the silicon dangling-bond resonance in polycrystalline (poly-Si) and amorphous silicon (a-Si:H) was measured. At room temperature, electron paramagnetic resonance (EPR) measurements reveal an isotropie g-value of 2.0055 and a line width of 6.5 and 6.1 G for Si dangling-bonds in a-Si:H and poly-Si, respectively. In both materials spin density and g-value are independent of temperature. While in a-Si:H the width of the resonance did not change with temperature, poly-Si exhibits a remarkable T dependence of ΔHpp. In unpassivated poly-Si a pronounced decrease of ΔHpp is observed for temperatures above 300 K. At 384 K ΔHpp reaches a minimum of 5.1 G, then increases to 6.1 G at 460 K, and eventually decreases to 4.6 G at 530 K. In hydrogenated poly-Si ΔHpp decreases monotonically above 425 K. The decrease of ΔHpp is attributed to electron hopping causing motional narrowing. An average hopping distance of 15 and 17.5 Å was estimated for unhydrogenated and H passivated poly-Si, respectively.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tao Wang ◽  
Zhubin Hu ◽  
Xiancheng Nie ◽  
Linkun Huang ◽  
Miao Hui ◽  
...  

AbstractAggregation-induced emission (AIE) has proven to be a viable strategy to achieve highly efficient room temperature phosphorescence (RTP) in bulk by restricting molecular motions. Here, we show that by utilizing triphenylamine (TPA) as an electronic donor that connects to an acceptor via an sp3 linker, six TPA-based AIE-active RTP luminophores were obtained. Distinct dual phosphorescence bands emitting from largely localized donor and acceptor triplet emitting states could be recorded at lowered temperatures; at room temperature, only a merged RTP band is present. Theoretical investigations reveal that the two temperature-dependent phosphorescence bands both originate from local/global minima from the lowest triplet excited state (T1). The reported molecular construct serves as an intermediary case between a fully conjugated donor-acceptor system and a donor/acceptor binary mix, which may provide important clues on the design and control of high-freedom molecular systems with complex excited-state dynamics.


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