Control of the binding energy by tuning the single dopant position, magnetic field strength and shell thickness in ZnS/CdSe core/shell quantum dot

2016 ◽  
Vol 84 ◽  
pp. 303-309 ◽  
Author(s):  
A. Talbi ◽  
E. Feddi ◽  
A. Zouitine ◽  
M. El Haouari ◽  
M. Zazoui ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Binding Energy ◽  
Quantum Dot ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Shell Thickness ◽  
Core Shell ◽  
Cdse Core

MAGNETIC FIELD, PRESSURE AND TEMPERATURE DEPENDENT OPTICAL PROPERTIES IN A GaAs 9.0 P 1.0 QUANTUM DOT

2014 ◽  
Vol 6 (2) ◽  
pp. 1178-1190
Author(s):  
A. JOHN PETER ◽  
Ada Vinolin
Keyword(s):  
Magnetic Field ◽  
Optical Properties ◽  
Quantum Dot ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Photon Energy ◽  
Nonlinear Optical ◽  
Binding Energies ◽  
Nonlinear Optical Properties ◽  
Optical Rectification

Simultaneous effects of magnetic field, pressure and temperature on the exciton binding energies are found in a 9.0 1.0 6.0 4.0 GaAs P / GaAs P quantum dot. Numerical calculations are carried out taking into consideration of spatial confinement effect. The cylindrical system is taken in the present problem with the strain effects. The electronic properties and the optical properties are found with the combined effects of magnetic field strength, hydrostatic pressure and temperature values. The exciton binding energies and the nonlinear optical properties are carried out taking into consideration of geometrical confinement and the external perturbations.Compact density approach is employed to obtain the nonlinear optical properties. The optical rectification coefficient is obtained with the photon energy in the presence of pressure, temperature and external magnetic field strength. Pressure and temperature dependence on nonlinear optical susceptibilities of generation of second and third order harmonics as a function of incident photon energy are brought out in the influence of magnetic field strength. The result shows that the electronic and nonlinear optical properties are significantly modified by the applications of external perturbations in a 9.0 1.0 6.0 4.0 GaAs P / GaAs P quantum dot.

scholarly journals Engineering Core-Shell Structures of Magnetic Ferrite Nanoparticles for High Hyperthermia Performance

Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 991 ◽  
Author(s):  
Mohamed S. A. Darwish ◽  
Hohyeon Kim ◽  
Hwangjae Lee ◽  
Chiseon Ryu ◽  
Jae Young Lee ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Cobalt Ferrite ◽  
Magnetic Core ◽  
Ferrite Nanoparticles ◽  
Shell Structures ◽  
Precipitation Process ◽  
Core Shell ◽  
Heating Efficiency

Magnetic ferrite nanoparticles (MFNs) with high heating efficiency are highly desirable for hyperthermia applications. As conventional MFNs usually show low heating efficiency with a lower specific loss power (SLP), extensive efforts to enhance the SLP of MFNs have been made by varying the particle compositions, sizes, and structures. In this study, we attempted to increase the SLP values by creating core-shell structures of MFNs. Accordingly, first we synthesized three different types of core ferrite nanoparticle of magnetite (mag), cobalt ferrite (cf) and zinc cobalt ferrite (zcf). Secondly, we synthesized eight bi-magnetic core-shell structured MFNs; Fe3O4@CoFe2O4 (mag@cf1, mag@cf2), CoFe2O4@Fe3O4 (cf@mag1, cf@mag2), Fe3O4@ZnCoFe2O4 (mag@zcf1, mag@zcf2), and ZnCoFe2O4@Fe3O4 (zcf@mag1, zcf@mag2), using a modified controlled co-precipitation process. SLP values of the prepared core-shell MFNs were investigated with respect to their compositions and core/shell dimensions while varying the applied magnetic field strength. Hyperthermia properties of the prepared core-shell MFNs were further compared to commercial magnetic nanoparticles under the safe limits of magnetic field parameters (<5 × 109 A/(m·s)). As a result, the highest SLP value (379.2 W/gmetal) was obtained for mag@zcf1, with a magnetic field strength of 50 kA/m and frequency of 97 kHz. On the other hand, the lowest SLP value (1.7 W/gmetal) was obtained for cf@mag1, with a magnetic field strength of 40 kA/m and frequency of 97 kHz. We also found that magnetic properties and thickness of the shell play critical roles in heating efficiency and hyperthermia performance. In conclusion, we successfully enhanced the SLP of MFNs by engineering their compositions and dimensions.

Magneto-biexciton in a group III–V diluted magnetic quantum dot

2014 ◽  
Vol 28 (27) ◽  
pp. 1450188 ◽  
Author(s):  
D. Lalitha ◽  
A. John Peter ◽  
Chang Woo Lee
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Optical Transition ◽  
Binding Energies ◽  
Mean Field Approximation ◽  
Magnetic Impurities ◽  
Spatial Confinement ◽  
G Factor

Binding energies of biexciton are computed in a GaMnAs / GaAlAs quantum dot with the effects of geometrical confinement, exchange interaction between the charge carrier and the magnetic impurities and the magnetic field. The size dependence of the binding energy of the biexciton in the presence of magnetic field is brought out. The optical transition energy, in the presence of magnetic field strength, is discussed for various magnetic impurities in a GaMn x As quantum dot. Numerical calculations are performed using variational technique. The spin polaronic energy of the biexciton with the effect of spatial confinement is carried out taking into account the mean field approximation in the presence of magnetic field strength. The magnetization of magnetic ion impurities as a function of dot radius is computed in a GaMn 0.02 As quantum dot. The effective g-factor as a function of spatial confinement is found in the GaMnAs quantum dot. The results show that the shift in spin polaron has more influence for the larger dot radius and the nonlinearity to linear behavior of g-factor for a particular dot size is achieved due to the sign reversal of Zeeman splitting.

THE EFFECTIVE MASS OF STRONG-COUPLING MAGNETOPOLARONS IN A PARABOLIC QUANTUM DOT

2011 ◽  
Vol 25 (32) ◽  
pp. 2419-2425 ◽  
Author(s):  
SHI-HUA CHEN ◽  
QING-ZHOU YAO
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Field Strength ◽  
Effective Mass ◽  
Magnetic Field Strength ◽  
Strong Coupling ◽  
Function Approximation ◽  
Gaussian Function ◽  
The Magnetic Field ◽  
Parabolic Quantum Dot

Within the framework of the Landau–Pekar variational method we have investigated the effective mass of strong-coupling magnetopolarons in a parabolic quantum dot. The effective mass as functions of the magnetic field strength and the confinement length of the quantum dot are obtained in the Gaussian function approximation. It is shown that the effective mass increases with the increasing magnetic field strength and increases with the decrease in the size of the quantum dot (QD).

Effect of Magnetic Field and Shell Thickness on Binding Energies of a ZnSe/ZnS Core Shell Quantum Dot

2016 ◽  
Vol 46 (2) ◽  
pp. 967-970 ◽  
Author(s):  
Bashir Mohi ud din Bhat ◽  
Muhammad Shunaid Parvaiz ◽  
Pratima Sen
Keyword(s):  
Magnetic Field ◽  
Quantum Dot ◽  
Shell Thickness ◽  
Binding Energies ◽  
Core Shell

On the Configuration of the Magnetic Field of β CrB

1976 ◽  
Vol 32 ◽  
pp. 613-622
Author(s):  
I.A. Aslanov ◽  
Yu.S. Rustamov
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Radial Velocity ◽  
Magnetic Field Strength ◽  
Complex Shape ◽  
Rotation Period ◽  
Field Variation ◽  
Magnetic Field Variation ◽  
Secular Variations ◽  
The Magnetic Field

SummaryMeasurements of the radial velocities and magnetic field strength of β CrB were carried out. It is shown that there is a variability with the rotation period different for various elements. The curve of the magnetic field variation measured from lines of 5 different elements: FeI, CrI, CrII, TiII, ScII and CaI has a complex shape specific for each element. This may be due to the presence of magnetic spots on the stellar surface. A comparison with the radial velocity curves suggests the presence of a least 4 spots of Ti and Cr coinciding with magnetic spots. A change of the magnetic field with optical depth is shown. The curve of the Heffvariation with the rotation period is given. A possibility of secular variations of the magnetic field is shown.

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