Thermoluminescence study on TlGaSSe layered single crystals

2014 ◽  
Vol 28 (16) ◽  
pp. 1450133 ◽  
Author(s):  
Serdar Delice ◽  
Nizami M. Gasanly
Keyword(s):  
Single Crystals ◽  
Heating Rate ◽  
Thermal Quenching ◽  
Activation Energies ◽  
Temperature Peak ◽  
Heating Rates ◽  
Quenching Effect ◽  
Defect Centers ◽  
General Order ◽  
Maximum Temperatures

The defect centers in TlGaSSe single crystals have been investigated by performing thermoluminescence (TL) measurements with various heating rates between 0.5 K/s and 1.0 K/s in the temperature range of 10–180 K. The TL spectra, with peak maximum temperatures at 39 K and 131 K, revealed the existences of two defect levels. Curve fitting, initial rise and peak shape methods were used to determine the activation energies of two defect centers. The experimental results also showed that the trapping process was dominated by second-order kinetics for the trap related with low temperature peak while the general order (mixed order) kinetics was dominant for the trap donated to high temperature peak. Furthermore, heating rate dependences and traps distributions were studied for two defect centers separately. Thermal quenching effect dominates the behavior of these defects as the heating rate is increased. Also, quasi-continuous distributions were established with the increase of the activation energies from 16 meV to 27 meV and from 97 meV to 146 meV for the traps associated with the peaks observed at low and high temperatures, respectively.

Investigation of defect levels in Bi12SiO20 single crystals by thermally stimulated current measurements

2021 ◽  
Author(s):  
Mehmet Isik ◽  
Serdar Delice ◽  
Nizami M Gasanly
Keyword(s):  
Heating Rate ◽  
Czochralski Method ◽  
Intrinsic Defect ◽  
Heating Rates ◽  
Thermally Stimulated Current ◽  
Rate Dependent ◽  
Defect Centers ◽  
Curve Fit ◽  
Maximum Temperatures ◽  
Kinetics Of

Abstract Bi12SiO20 (BSO) single crystal belongs to the sillenite semiconducting family known as defective compounds. The present paper investigates the defect centers in BSO grown by Czochralski method by means of thermally stimulated current (TSC) measurements performed in the 10-260 K range. The TSC glow curve obtained at heating rate of β = 0.1 K/s presented several peaks associated with intrinsic defect centers. The activation energies of defect centers were revealed as 0.09, 0.15, 0.18, 0.22, 0.34, 0.70 and 0.82 eV accomplishing the curve fit analyses method. The peak maximum temperatures and orders of kinetics of each deconvoluted peak were also determined as an outcome of fitting process. TSC experiments were expanded by making the measurements at various heating rates between 0.1 and 0.3 K/s to get information about the heating rate dependent peak parameters.

A NEW THERMOLUMINESCENCE GENERAL ORDER GLOW CURVE FIT FUNCTION CONSIDERING THERMAL QUENCHING EFFECT

2019 ◽  
Vol 187 (1) ◽  
pp. 103-107
Author(s):  
S Harooni ◽  
M Zahedifar ◽  
E Sadeghi ◽  
Z Ahmadian
Keyword(s):  
Kinetic Parameters ◽  
Glow Curve ◽  
Thermal Quenching ◽  
Glow Peak ◽  
Heating Rates ◽  
Order Model ◽  
Quenching Effect ◽  
Fitting Procedure ◽  
Curve Fit ◽  
General Order

Abstract A new thermoluminescence (TL) general order glow curve fit function in terms of the intensity of peak maximum, Im and the peak temperature, Tm is presented in which thermal quenching (TQ) effect has been taken into account. Also, the conventional general order model and the new presented function were fitted to the glow peak 5 of LiF:Mg,Ti (TLD-100) and the kinetic parameters were obtained for different heating rates as the results of fitting procedure. It was found that increasing the heating rate, which makes the TQ more prominent, causes more divergence between the kinetic parameters extracted by applying two models. Considering that the TL intensity and the glow peak area reduce with shifting the glow peak to higher temperatures as a result of TQ, the new presented function gives more reliable results for the kinetic parameters.

scholarly journals Электрически активные состояния захвата и переноса заряда, обусловливающие медленную рекомбинацию в кристаллах бромида таллия при низких температурах

2018 ◽  
Vol 52 (2) ◽  
pp. 171
Author(s):  
В. Кажукаускас ◽  
Р. Гарбачаускас ◽  
С. Савицки
Keyword(s):  
Activation Energy ◽  
Electric Field ◽  
Single Crystals ◽  
Applied Electric Field ◽  
Thermal Activation ◽  
Thermal Quenching ◽  
Activation Energies ◽  
Trap States ◽  
Optical Generation ◽  
Stockbarger Method

AbstractTlBr single crystals grown by the Bridgman–Stockbarger method are studied. It is established that frozen-conductivity effects manifest themselves under interband excitation by light at temperatures below 200 K. Herewith, clearly pronounced superlinear dependences of the induced photoconductivity on the strength of the applied electric field manifest themselves. The results of studying thermally stimulated conductivity evidence that these phenomena can be associated with the filling of trap states with thermal activation energies of 0.08–0.12 eV. This state can be removed due to thermal quenching at temperatures of ≳180 K because of the emptying of energy states with an activation energy of 0.63–0.65 eV filled after optical generation.

scholarly journals Effect of Heating Rate on the Responses of LiF: Mg, Cu, Na, Si Thermoluminescent Phosphor

2011 ◽  
Vol 21 (1) ◽  
pp. 43 ◽  
Author(s):  
Vu Thi Thai Ha ◽  
Nguyen Thi Quy Hai ◽  
Nguyen Ngoc Long
Keyword(s):  
Heating Rate ◽  
Peak Height ◽  
Glow Peak ◽  
Maximum Temperature ◽  
Full Width ◽  
Half Maximum ◽  
Temperature Peak ◽  
Heating Rates ◽  
First Order ◽  
Area Increase

In the current work the glow curves for LiF:Mg,Cu,Na,Si thermoluminescent material were measured and analyzed by using a function approximating to the well-known Randall-Wilkins first-order expression. The influence of different heating rates on thermoluminescent glow-peak maximum temperature, peak height and integrated area of the glow peak was investigated for LiF:Mg,Cu,Na,Si phosphor. The results show that the glow-peak temperature, peak height and glow peak area increase with increasing heating rate, while the full width at half maximum of glow peak almost keeps constant in the range of heating rates studied.

Thermal Quenching and Antiquenching of Photoluminescence in Solution-Grown Cs4PbBr6 Perovskite Single Crystals

2021 ◽  
Author(s):  
Mingming Chen ◽  
Shuaiheng Yang ◽  
Youwen Yuan ◽  
Xuemin Shen ◽  
Yuan Liu ◽  
...  
Keyword(s):  
Single Crystals ◽  
Thermal Quenching

Maximum heating rates for producing undistorted glassy carbon ware determined by wedge-shaped samples

1996 ◽  
Vol 11 (9) ◽  
pp. 2368-2375 ◽  
Author(s):  
Hossein Maleki ◽  
Lawrence R. Holland ◽  
Gwyn M. Jenkins ◽  
R. L. Zimmerman ◽  
Wally Porter
Keyword(s):  
Heating Rate ◽  
Treatment Process ◽  
Gaseous Product ◽  
Pyrolysis Mass Spectrometry ◽  
Heating Rates ◽  
Gaseous Products ◽  
Volatile Products ◽  
Solid Bodies ◽  
Polymeric Carbon ◽  
Maximum Heating

Polymeric carbon artifacts are particularly difficult to make in thick section. Heating rate, temperature, and sample thickness determine the outcome of carbonization of resin leading to a glassy polymeric carbon ware. Using wedge-shaped samples, we found the maximum thickness for various heating rates during gelling (300 K–360 K), curing (360 K–400 K), postcuring (400 K–500 K), and precarbonization (500 K–875 K). Excessive heating rate causes failure. In postcuring the critical heating rate varies inversely as the fifth power of thickness; in precarbonization this varies inversely as the third power of thickness. From thermogravimetric evidence we attribute such failure to low rates of diffusion of gaseous products of reactions occurring within the solid during pyrolysis. Mass spectrometry shows the main gaseous product is water vapor; some carboniferous gases are also evolved during precarbonization. We discuss a diffusion model applicable to any heat-treatment process in which volatile products are removed from solid bodies.

scholarly journals Towards a better representation of the solar cycle in general circulation models

2007 ◽  
Vol 7 (20) ◽  
pp. 5391-5400 ◽  
Author(s):  
K. M. Nissen ◽  
K. Matthes ◽  
U. Langematz ◽  
B. Mayer
Keyword(s):  
Solar Cycle ◽  
Heating Rate ◽  
General Circulation ◽  
Temperature Response ◽  
General Circulation Models ◽  
Short Wave ◽  
Radiative Transfer Model ◽  
Transfer Model ◽  
Heating Rates ◽  
Radiation Scheme

Abstract. We introduce the improved Freie Universität Berlin (FUB) high-resolution radiation scheme FUBRad and compare it to the 4-band standard ECHAM5 SW radiation scheme of Fouquart and Bonnel (FB). Both schemes are validated against the detailed radiative transfer model libRadtran. FUBRad produces realistic heating rate variations during the solar cycle. The SW heating rate response with the FB scheme is about 20 times smaller than with FUBRad and cannot produce the observed temperature signal. A reduction of the spectral resolution to 6 bands for solar irradiance and ozone absorption cross sections leads to a degradation (reduction) of the solar SW heating rate signal by about 20%. The simulated temperature response agrees qualitatively well with observations in the summer upper stratosphere and mesosphere where irradiance variations dominate the signal. Comparison of the total short-wave heating rates under solar minimum conditions shows good agreement between FUBRad, FB and libRadtran up to the middle mesosphere (60–70 km) indicating that both parameterizations are well suited for climate integrations that do not take solar variability into account. The FUBRad scheme has been implemented as a sub-submodel of the Modular Earth Submodel System (MESSy).

INVESTIGATION OF THERMAL DEGRADATION OF POULTRY PROCESSING DEWATERED SLUDGE USING THERMOGRAVIMETRIC ANALYSIS METHOD

2015 ◽  
Vol 76 (5) ◽  
Author(s):  
N. Aniza ◽  
S. Hassan ◽  
M. F. M. Nor ◽  
K. E. Kee ◽  
Aklilu T.
Keyword(s):  
Particle Size ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Heating Rate ◽  
Degradation Process ◽  
Heating Rates ◽  
Initial Stage ◽  
Poultry Processing ◽  
Effect Of Particle Size ◽  
Dewatered Sludge

Thermal degradation of Poultry Processing Dewatered Sludge (PPDS) was studied using thermogravimetric analysis (TGA) method. The effect of particle size on PPDS samples and operational condition such as heating rates were investigated. The non-isothermal TGA was run under a constant flow of oxygen at a rate of 30 mL/min with temperature ranging from 30ºC to 800ºC. Four sample particle sizes ranging between 0.425 mm to 2 mm, and heating rate between 5 K/min to 20 K/min were used in this study. The TGA results showed that particle size does not have any significant effect on the thermogravimetry (TG) curves at the initial stage, but the TG curves started to separate explicitly at the second stage. Particle size may affect the reactivity of sample and combustion performance due to the heat transfer and temperature gradient. The TG and peak of derivative thermogravimetry (DTG) curves tend to alter at high temperature when heating rate is increased most likely due to the limitation of mass transfer and the delay of degradation process. 

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