Temperature dependence of the Faraday rotation in diluted magnetic semiconductors Cd1−−Mn Zn Te crystals

In this work the structural, optical and electrical properties of Cd1-x-yMnxZnyTe single crystals (x=0.10, 0.20, y=0.15) grown by the vertical Bridgman method were investigated. Based on differential thermal analysis (DTA) results, it was found that the crystallization rate increases as the crystallization temperature (Ts) decreases. It is determined that the volume fraction of solid phase in Cd0.75Mn0.10Zn0.15Te and Cd0.65Mn0.20Zn0.15Te alloys decrease to a minimum in the temperature ranges 1366-1389 K and 1363-1388 K, respectively. The activation energies of melting and crystallization processes for these alloys under different conditions are established. The linear character of the dependence between the preexponential factor (lnϕsol.phase,0 and lnVmelt., sol. phase,0) and the activation energy of these processes is determined, which is evidence of a compensation effect. The band-gap value was estimated to be ~ 1.73 eV for Cd0.75Mn0.10Zn0.15Te and ~1.84 eV for Cd0.65Mn0.20Zn0.15Te at 300 K. Typical transmission images showed the presence of small Te inclusions (5-10 µm) in the crystals. The electrical resistivity, obtained from the I-V curves, was ~10 4 Ώ•cm for both crystals and decreased slightly toward the end of the ingots.

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“…Fig. 8b illustrates a comparison of XRD data for as-grown crystal Cd0.65Mn0.20Zn0.15Te (g = 0.5) with XRD peaks of Cd0.50Mn0.35Zn0.15Te [14].…”

Section: Cd1-x-ymnxznyte Crystals Growth and Characterizationsmentioning

confidence: 99%

Thermodynamics and crystal growth of Cd1-x-yMnxZnyTe (x=0.10, 0.20, y=0.15)

Kopach

Shcherbak

et al. 2021

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXIII

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“…The source for the larger values of the Verdet constant in DMS has been traced down to the GZS of the energy band states near the band gap resonance. Although most research has focused on achieving a larger Verdet constant with various MO materials, especially Cd 1−x Mn x Te, these studies have been restricted only to bulk DMS [10,[43][44][45][46] and epitaxial heterostructures in the form of wells [47][48][49][50][51] and dots [11,25,52]. Therefore, investigating the impact of sp-d exchange interaction on the GFR in DMS heterostructures with various topologies, like QR, would generate unprecedented interest in developing high-quality epitaxial structures for various technological applications.…”

Section: Introductionmentioning

confidence: 99%

Giant excitonic magneto-optical Faraday rotation in single semimagnetic CdTe/Cd_{1-x}Mn_{x}Te quantum ring

Panneerselvam¹,

Muralidharan²

2023

Preprint

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Magnetic tuning of the bound exciton states and corresponding giant Zeeman splitting (GZS) between σ + and σ − excitonic transitions in CdTe/Cd1−xMnxTe quantum ring has been investigated in the Faraday configuration for various concentrations of Mn 2+ ions, using the variational technique in the effective mass approximation. The sp-d exchange interaction between the localized magnetic impurity ions and the delocalized charge carriers has been accounted via mean-field theory with the inclusion of a modified Brillouin function. The enhancement of the GZS, and in turn, the effective g-factor with the application of an external magnetic field, is strikingly manifested in type-I -type-II transition in the band structure, which has been well explained by computing the overlap integral between the electron and hole, and the in-plane exciton radius. This highlights the extraordinary magneto-optical properties, including the giant Faraday rotation and associated Verdet constant, which have been calculated using single oscillator model. The oscillator strength and exciton lifetime have been estimated, and are found to be larger than in the bulk diluted magnetic semiconductors (DMS) and quantum wells, reflecting stronger confinement inside the quantum ring. The results show that the DMS-based quantum ring exhibits more extensive Zeeman splitting, which gives rise to ultra-high Verdet constant of 2.6 × 10 9 rad/Tesla/m, which are a few orders of magnitude larger than in the existing quantum systems and magneto-optical materials.

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Section: Introductionmentioning

confidence: 99%

“…In the past, the diluted magnetic semiconductors Cd1-x-yMnxZnyTe attracted attention of researchers due to their magneto-optical properties, the band-gap width, Faraday rotation [2,3] and ferromagnetism in Cd1-yMn0.35ZnyTe single crystals [4]. Until now CMZT crystals were grown by a VB method [1][2][3] and the temperature-gradient solution method [4]. However, in these studies, no information was available regarding the liquidus-solidus temperatures in the composition range for the Cd1-x-yMnxZnyTe solid solutions [2][3][4] beyond a diagram for the Cd1-x-yMnxZnyTe pseudoternary alloys [1] showing the concentration dependencies for constant lattice parameters.…”

Section: Introductionmentioning

confidence: 99%

“…Until now CMZT crystals were grown by a VB method [1][2][3] and the temperature-gradient solution method [4]. However, in these studies, no information was available regarding the liquidus-solidus temperatures in the composition range for the Cd1-x-yMnxZnyTe solid solutions [2][3][4] beyond a diagram for the Cd1-x-yMnxZnyTe pseudoternary alloys [1] showing the concentration dependencies for constant lattice parameters.…”

Section: Introductionmentioning

confidence: 99%

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Properties of Cd0.90-xMnxZn0.10Te (x = 0.10, 0.20) crystals grown by Vertical Bridgman method

Kopach

Kanak

et al. 2018

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XX

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The correlation between Cd0.90-xMnxZn0.10Te (CMZT) melt state and structural properties of the crystals, grown by vertical Bridgman method, was investigated. The Cd0.9-xMnxZn0.1Te crystals with various Mn compositions (x = 0.1 and 0.2) were grown by a two-step method from high-purity elemental components. We have conducted a series of crystal growth runs with different degrees of melt superheating over the alloy's melting temperature. We obtained ingots with various crystalline structures and properties. It was concluded that the best crystals were grown from the melt with a thermal gradient of about 5 °C/cm during growth process. We have found that the band-gap increases (from 1.67 eV at x=0.1 to 1.79 eV at x=0.2) with Mn content.

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Temperature dependence of the Faraday rotation in diluted magnetic semiconductors Cd1−−Mn Zn Te crystals

Cited by 7 publications

References 7 publications

Thermodynamics and crystal growth of Cd1-x-yMnxZnyTe (x=0.10, 0.20, y=0.15)

Thermodynamics and crystal growth of Cd1-x-yMnxZnyTe (x=0.10, 0.20, y=0.15)

Giant excitonic magneto-optical Faraday rotation in single semimagnetic CdTe/Cd_{1-x}Mn_{x}Te quantum ring

Properties of Cd0.90-xMnxZn0.10Te (x = 0.10, 0.20) crystals grown by Vertical Bridgman method

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