scholarly journals A Two-Step Annealing Method to Enhance the Pyroelectric Properties of Mn:PIMNT Chips for Infrared Detectors

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2562
Author(s):  
Rongfeng Zhu ◽  
Jing Zhao ◽  
Jianwei Chen ◽  
Bijun Fang ◽  
Haiqing Xu ◽  
...  

Mn:0.15Pb(In1/2Nb1/2)O3-0.55Pb(Mg1/3Nb2/3)O3-0.30PbTiO3 (Mn:PIMNT) pyroelectric chips were prepared by a two-step annealing method. For the two steps, annealing temperatures dependence of microstructure, defects, surface stress, surface roughness, dielectric properties and pyroelectric properties were studied comprehensively. The controlling factors influencing the pyroelectric properties of the Mn:PIMNT crystals were analyzed and the optimum annealing temperature ranges for the two steps were determined: 600–700 °C for the first step and 500–600 °C for the second step. The pyroelectric properties of the thin Mn:PIMNT chips were significantly enhanced by the two-step annealing method via tuning oxygen vacancies and eliminating surface stress. Based on Mn:PIMNT pyroelectric chips annealed at the most favorable conditions (annealed at 600 °C for the first step and 500 °C for the second step), infrared detectors were prepared with specific detectivity D* = 1.63 × 109 cmHz1/2W−1, nearly three times higher than in commercial LiTaO3 detectors.

Crystals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 387 ◽  
Author(s):  
Pengfei Yu ◽  
Yongren Chen ◽  
Wei Li ◽  
Wenfei Liu ◽  
Bin Liu ◽  
...  

A multi-step annealing method was successfully applied to inclusions reduction and resistivity improvement of CdMnTe:In (CMT:In) single crystals with high resistivity, including a Cd atmosphere annealing step followed by a Te atmosphere annealing step. After the Cd atmosphere annealing step, the density of Te inclusions was reduced distinctly, and it could be also decreased in the subsequent step of re-annealing under Te atmosphere. Both the resistivity and IR transmittance decreased notably after Cd atmosphere annealing, whereas they increased tremendously after re-annealing under a Te atmosphere. The reduction of full-width at-half-maximum (FWHM) and the increase of the intensity of the X-ray rocking curve indicated an improvement of the crystal quality. Meanwhile, after Cd atmosphere annealing, the increase of the intensity of the (D0,X) peak and the disappearance of the (A0,X) peak in photoluminescence (PL) measurements suggested further that the crystal quality was improved. The detector performance was enhanced obviously after annealing. The higher the annealing temperature, the better the performance was. The detector fabricated by CMT:In slice (Cd atmosphere annealing at 1073 K for 240 h and Te atmosphere re-annealing at 773 K for 120 h) with 9.43% energy resolution and 1.25 × 10−3 cm2/V μτ value had the best detector performance.


2004 ◽  
Vol 810 ◽  
Author(s):  
Moongyu Jang ◽  
Yarkyeon Kim ◽  
Jaeheon Shin ◽  
Kyoungwan Park ◽  
Seongjae Lee

ABSTRACTThe stable growth conditions of erbium-silicide on silicon-on-insulator (SOI) are investigated considering annealing temperature, SOI and sputtered erbium thickness. From the sheet resistance measurement, X-ray diffraction and Auger electron spectroscopy analysis, the optimum annealing temperature is determined as 500°C. Also, for the stable growth of erbium- silicide on SOI, the sputtered erbium thickness should be less than 1.5 times of SOI thickness. As the SOI thickness decreases below this critical thickness, erbium-rich region is formed at the erbium-silicide and buried-oxide interface. By applying the optimized erbium-silicide growth conditions, 50-nm-gate-length n-type SB-MOSFET is manufactured, which shows the possible usage of erbium-silicide as the source and drain material in the n-type Schottky barrier MOSFETs for decananometer regime applications.


Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 901
Author(s):  
Jie Chen ◽  
Yonghao Zhang ◽  
Jiqiang Ge ◽  
Huabei Peng ◽  
Shuke Huang ◽  
...  

To improve the shape memory effect (SME) of 304 austenitic steel effectively and efficiently, thermomechanical cycling, comprising deformation at room temperature and annealing, was applied. The influences of cycle number and annealing temperature on the SME and microstructures in 304 austenitic steel were investigated by light microscope (LM), X-ray diffraction (XRD), and transmission electron microscope (TEM). The shape recovery ratio was remarkably improved from 16% to 40% after two thermomechanical cycles. The optimum annealing temperature was 833 K in the process of thermomechanical cycling. The improved SME by thermomechanical cycling was mainly related to stress-induced ε martensite rather than stress-induced α’ martensite. The reason is that thermomechanical cycling can not only promote the occurrence of the stress-induced γ→ε martensitic transformation, but also suppress the subsequently stress-induced ε→α′ transformation.


1999 ◽  
Vol 4 (S1) ◽  
pp. 684-690
Author(s):  
X. A. Cao ◽  
F. Ren ◽  
J. R. Lothian ◽  
S. J. Pearton ◽  
C. R. Abernathy ◽  
...  

Sputter-deposited W-based contacts on p-GaN (NA∼1018 cm−3) display non-ohmic behavior independent of annealing temperature when measured at 25°C. The transition to ohmic behavior occurs above ∼250°C as more of the acceptors become ionized. The optimum annealing temperature is ∼700°C under these conditions. These contacts are much more thermally stable than the conventional Ni/Au metallization, which shows a severely degraded morphology even at 700°C. W-based contacts may be ohmic as-deposited on very heavily doped n-GaN, and the specific contact resistance improves with annealing up to ∼900°C.


2011 ◽  
Vol 291-294 ◽  
pp. 860-863 ◽  
Author(s):  
Min Li Wang ◽  
Zhi Wang Zheng ◽  
Gong Ting Zhang

The salt-bath annealing was used to study the recrystallization of structural steels as well as the effect of chemical compositions on the microstructure and properties of structural hot dip galvanized steel sheets was investigated in term with the production condition of the No.2 hot dip galvanizing line in Pangang. The optimum annealing temperature range was determined. Experimental results show that the recrystallization temperature of Grade40 and Grade33 is approximately 720°C and 680°C, respectively. Considering the stability of mechanical properties, their optimum annealing temperature are determined to be approximately 720°C. The recrystallization temperature of Grade50 is above 700°C. In order to ensure the margin of strength and the stability of properties of Grade50, the optimum annealing temperature is approximately 780°C.


2012 ◽  
Vol 486 ◽  
pp. 519-523 ◽  
Author(s):  
Kai Fa Wang ◽  
Bao Lin Wang

In this paper, we analyze the influence of surface effects including residual surface stress, surface piezoelectric and surface elasticity on the buckling behavior of piezoelectric nanobeams by using the Timoshenko beam theory and surface piezoelectricity model. The critical electric potential for buckling of piezoelectric nanobeams with different boundary condition is obtained analytically. From the results, it is found that the surface piezoelectric reduces the critical electric potential. However, a positive residual surface stress increases the critical electric potential. In addition, the shear deformation reduces the critical electric potential, and the influence of shear deformation become more significant for a stubby piezoelectric nanobeam.


2009 ◽  
Vol 92 (12) ◽  
pp. 3132-3134 ◽  
Author(s):  
Guangzu Zhang ◽  
Shenglin Jiang ◽  
Yike Zeng ◽  
Yangyang Zhang ◽  
Qingfeng Zhang ◽  
...  

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Alejandro Gonzalez-Martinez ◽  
Alejandro Rodriguez-Sanchez ◽  
Belén Rodelas ◽  
Ben A. Abbas ◽  
Maria Victoria Martinez-Toledo ◽  
...  

Identification of anaerobic ammonium oxidizing (anammox) bacteria by molecular tools aimed at the evaluation of bacterial diversity in autotrophic nitrogen removal systems is limited by the difficulty to design universal primers for theBacteriadomain able to amplify the anammox 16S rRNA genes. A metagenomic analysis (pyrosequencing) of total bacterial diversity including anammox population in five autotrophic nitrogen removal technologies, two bench-scale models (MBR and Low Temperature CANON) and three full-scale bioreactors (anammox, CANON, and DEMON), was successfully carried out by optimization of primer selection and PCR conditions (annealing temperature). The universal primer 530F was identified as the best candidate for total bacteria and anammox bacteria diversity coverage. Salt-adjusted optimum annealing temperature of primer 530F was calculated (47°C) and hence a range of annealing temperatures of 44–49°C was tested. Pyrosequencing data showed that annealing temperature of 45°C yielded the best results in terms of species richness and diversity for all bioreactors analyzed.


2011 ◽  
Vol 10 (04n05) ◽  
pp. 861-865 ◽  
Author(s):  
T. P. YADAV ◽  
DEVINDER SINGH ◽  
N. K. MUKHOPADHYAY ◽  
M. A. SHAZ ◽  
R. S. TIWARI ◽  
...  

In the present investigation, ( Cu, Cr, Fe ) Al 2O4 spinel was synthesized from decagonal quasicrystalline precursor using mechanical milling followed by air annealing. The optimum annealing temperature and time were found to be 600°C and 60 h respectively. The evolution of the spinel structure started upon air annealing at 600°C from the B2 phase formed due to milling of quasicrystalline phase for 40 h. The relevant optical property of mechanically milled and air annealed samples prepared at different temperatures (400°C, 500°C and 600°C) were evaluated by photoluminescence technique. These studies suggested the presence of emission characteristics in blue region i.e. at 430 nm.


2011 ◽  
Vol 335-336 ◽  
pp. 981-984
Author(s):  
Xi Gui Wang ◽  
Xiao Xian Wang

Eu3+doped LaF3-SiO2nano-composite material were synthesized by sol-gel method at room temperature, and the structure and properties were characterized by XRD, TG-DTA, IR, excitation and emission spectrum. The structure indicated that the optimal doping formula for preparing nano-materials was La5Si95that transformed into a stable mineral structure of cerium fluoride, and mainly found Si-O-Si bonds when the temperature was above 500 °C. Luminous property researches showed that the optimum annealing temperature was 500 °C. The best excitation wavelength was 395 nm when the monitoring wavelength was 612 nm, and the optimal doping molar concentration of Eu3+was 0.35 mol %.


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