Structural and transport investigation of Cd1−Mn Te semimagnetic semiconductor system

Wahab, L. A.; Makram, N.; Hantour, H.

doi:10.1016/j.jrras.2013.12.002

Cited by 3 publications

(3 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The temperature dependence of the entropy obtained for different concentrations of Mn in compound of the investigated samples is shown in Fug. (7).…”

Section: δS M (T H) = ) H Dhmentioning

confidence: 99%

“…The study of some magnetic properties of the compounds represents a convenient method of determining the degree of order in such alloys. It has been shown for MnIII 2 VI 4 compounds, that, those alloys in which the Mn is disordered, have very different magnetic behavior from those showing an ordered Mn arrangement [6][7]. The study found that when the Mn atoms are ordered on the cation sublattice the compound shows almost ideal antiferromagnetc behavior.…”

Section: Introductionmentioning

confidence: 96%

See 1 more Smart Citation

Magnetic and Thermal Properties of Semimagnetic Semiconductors

2015

Egyptian Journal of Solids

View full text Add to dashboard Cite

Measurements of the dynamic magnetic susceptibility χ as a function of temperature were made on polycrystalline semimagnetic semiconductor Cd 1-x Mn x Se (x = 0.1, 0.2 and 0.3). The magnetic susceptibility was investigated in the temperature range of 5-200K revealing the paramagnetic behavior described by the Curie-Weiss law and indicating the presence of antiferromagnetic exchange interactions between Mn ions. The 1/ χ m versus T curves indicates that for x=0.1 the behavior was a mixture of antiferromagnetic and spin-glass while for x = 0.2 and 0.3 shows spin-glass form. The temperature dependence of the EPR spectra for the investigated samples was measured in the temperature range 4 to 300k. The obtained g-factor of the investigated samples shows slight decrease with increasing the concentration of Mn. The calculated number of defects illustrates that increasing the temperature leads to an increase in the number of defects increases.

show abstract

“…The temperature dependence of the entropy obtained for different concentrations of Mn in compound of the investigated samples is shown in Fug. (7).…”

Section: δS M (T H) = ) H Dhmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 96%

Magnetic and Thermal Properties of Semimagnetic Semiconductors

2015

Egyptian Journal of Solids

View full text Add to dashboard Cite

show abstract

“…The magnetic properties of Cd 1– x Mn x Te have been extensively investigated; − however, the study of parameters that affect the diffusion of Mn 2+ ions and V Cd into ultrasmall quantum dots (USQDs) by optical properties have not yet been discussed. Therefore, we used photoluminescence (PL) and electron paramagnetic resonance (EPR) techniques to study the effect of manganese concentration and thermal annealing time on the optical properties of Cd 1– x Mn x Te USQDs.…”

Section: Introductionmentioning

confidence: 99%

Controlling Densities of Manganese Ions and Cadmium Vacancies in Cd_1–xMn_xTe Ultrasmall Quantum Dots in a Glass Matrix: x-Concentration and Thermal Annealing

et al. 2015

View full text Add to dashboard Cite

In this work, we used nominal concentration (x) and thermal annealing to control the density of manganese (Mn 2+ ) ions and cadmium vacancies (V Cds ) in Cd 1−x Mn x Te ultrasmall quantum dots (USQDs) embedded in a glass matrix. The physical properties were investigated by photoluminescence (PL) and electron paramagnetic resonance (EPR). PL bands related to surface defects and Mn 2+ ions intensified, whereas bands related to V Cds decreased with increasing manganese concentration. Longer thermal annealing times caused decreases in the intensity of PL bands characteristic of Mn 2+ ions and V Cds . The EPR spectra confirmed that manganese exhibited +2 oxidation states and was incorporated at the core and surface of the Cd 1−x Mn x Te USQDs. Furthermore, the quantities of Mn 2+ ions within the Cd 1−x Mn x Te USQDs confirmed that longer thermal annealing times were associated with constant diffusion of these ions from the core to the surface and then the glass. Therefore, we demonstrated that longer thermal annealing times and higher manganese concentrations make it possible to control both the emissions intensities related to V Cds and Mn 2+ ions and the diffusion of these ions to the surface and then the glass. ■ INTRODUCTIONDiluted magnetic semiconductor (DMS) nanocrystals (NCs) are materials in which some sites are substituted by impurities, typically manganese. DMSs are represented by A 1−x Mn x B, where x denotes the fraction of impurities. Manganese with +2 oxidation states (Mn 2+ ions) is easily incorporated into the II− VI NCs by replacing group II cations. When Mn 2+ ions occupy Cd sites in a cubic CdTe crystal, their free-ion terms split due to the cubic crystal field. 1 Manganese-doped II−VI and III−V semiconductor NCs have been studied extensively because of their interesting properties and numerous applications. 2−5 For example, group II cations (Zn, Cd, and Hg) and group VI anions (S, Se, and Te) doped with Mn 2+ ions have been used in magneto-optical devices. 6 Diverse applications are possible because of the exchange interaction between the electronic subsystem (sp-band electrons of the host semiconductor) and the electrons originating in the partially filled d or f levels of the magnetic ions constituting the DMS. This exchange interaction enables control over the electronic and optical properties of the material using external magnetic fields.The optical properties of semiconductor NCs can be altered by quantum confinement effects, which are tuned to the size and shape of nanocrystals called quantum dots (QDs). Regarding DMS, exchange interactions between magnetic ions and host nonmagnetic semiconductors strengthen as NC sizes diminish. Furthermore, the electronic paramagnetic resonance (EPR) technique showed these ions may be incorporated at different crystallographic sites within the crystal, (e.g., in the nucleus or at the surface). Thus, identifying these magnetic ions makes it possible to trace their migration from the core to the surface regions of the NCs and to quantify their local densitie...

show abstract

Kinetic parameters of Cd0.85-xMnxZn0.15Te (x = 0.05-0.20) alloys melting and crystallization processes

Rusnak

Matviy

Kopach

et al. 2019

Chernivtsi University Scientific Herald. Chemistry

View full text Add to dashboard Cite

The kinetic parameters of melting and crystallization of Cd0.85-xMnxZn0.15Te (x = 0.05-0.20) alloys were investigated by the differential thermal analysis (DTA) method at different heating/cooling rates. Cd0.85-xMnxZn0.15Te alloys were synthesized from elementary materials in a vertical furnace with a high-gradient temperature that prevented the sublimation of the components. The DTA was carried out in an automatic system. The heating and cooling rates were 5 and 10°С/min, and the dwell time was 10, 30 and 60 minutes. The DTA were processed in two different ways. Using the first treatment method we found that the melt of the Cd0.80Mn0.05Zn0.15Te alloy crystallize with the supercooling, and it occurs at melt superheating higher than 12 °С. But the melt’s “negative” supercooling effect is present for alloy when the melt are superheated to 12 °C compared to the melting temperature of the alloy, which is evidence of two-phase alloy (solid phase - melt) at these temperatures. Also we determined that as the holding temperature increases the crystallization temperature decreases and the crystallization rate increases. We investigated that the area of the crystallization effect increases with increasing holding temperature. Concerning on the second treatment method we found the dependence of the solid-state volume fraction (φsolid state) versus the intermediate dwell temperature of the alloy during the heating process for Cd0.80Mn0.05Zn0.15Te. It shows that increasing of the melt-dwell temperature led to the melts full homogenization only near 1117 °C. Thus according to our previous researches we can say that the Cd1-x-уMnxZnyTe alloy’s melting temperature increases with ZnTe concentration increasing: ~1100-1102°С for Cd0.95-xMnxZn0.05Te alloys (x=0.05-0.30), ~1102-1104°С for Cd0.90-xMnxZn0.10Te alloys (x=0.05-0.30) and ~1116-1119°С for Cd0.80Mn0.05Zn0.15Te alloys.

show abstract

Structural and transport investigation of Cd1−Mn Te semimagnetic semiconductor system

Cited by 3 publications

References 11 publications

Magnetic and Thermal Properties of Semimagnetic Semiconductors

Magnetic and Thermal Properties of Semimagnetic Semiconductors

Controlling Densities of Manganese Ions and Cadmium Vacancies in Cd_1–xMn_xTe Ultrasmall Quantum Dots in a Glass Matrix: x-Concentration and Thermal Annealing

Kinetic parameters of Cd0.85-xMnxZn0.15Te (x = 0.05-0.20) alloys melting and crystallization processes

Contact Info

Product

Resources

About

Structural and transport investigation of Cd1−Mn Te semimagnetic semiconductor system

Cited by 3 publications

References 11 publications

Magnetic and Thermal Properties of Semimagnetic Semiconductors

Magnetic and Thermal Properties of Semimagnetic Semiconductors

Controlling Densities of Manganese Ions and Cadmium Vacancies in Cd1–xMnxTe Ultrasmall Quantum Dots in a Glass Matrix: x-Concentration and Thermal Annealing

Kinetic parameters of Cd0.85-xMnxZn0.15Te (x = 0.05-0.20) alloys melting and crystallization processes

Contact Info

Product

Resources

About

Controlling Densities of Manganese Ions and Cadmium Vacancies in Cd_1–xMn_xTe Ultrasmall Quantum Dots in a Glass Matrix: x-Concentration and Thermal Annealing