Magnetic phase diagram of Pb1−−Sn Mn Te semimagnetic semiconductors

“…Due to the limited solubility of Mn magnetic ions in IV-VI matrices (x < 0.1), the ferromagnetic transition in these materials is typically below TC ≤ 30 K. The ferromagnetic exchange interactions in IV-VI semimagnetic semiconductors originate from the Ruderman-Kittel-Kasuya-Yoshida (RKKY) mechanism [10][11][12][13]. In the RKKY mechanism the interspin coupling is brought about by the spin polarization,of conducting carriers interacting via the sp-d exchange with the localized magnetic moments of magnetic ions.…”

Section: T Storymentioning

confidence: 99%

Semiconductor Ferromagnetic Structures

Story

2000

Acta Phys. Pol. A

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Ferromagnetic semiconductor structures such as superlattices or trilayers form a new class of magnetic systems composed entirely of semiconductor materials. The examples are Ga 1-x Mnx As-AlGaAs with the ferromagnetic layer of GaMnAs semimagnetic (diluted magnetic) semiconductor or EuS-PbS with the ferromagnetic member (EuS) of the family of europium chalcogenides. We discuss the spectrum of perspective ferromagnetic semiconductor materials, the effect of size and stress on magnetic properties of ultrathin semiconductor ferromagnetic layers, and the effect of interlayer exchange in all-semiconductor systems.

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“…At the same time, unlike the case of short range interactions, the length scale of magnetic correlation is set by λ F , not byr. This means that for λ F ≫r the critical fluctuations of magnetization will be strongly suppressed, an expectation corroborated by the virtual absence of critical scattering of the carriers by the Mn spins in bulk Pb 1−x−y Mn x Sn y Te [26], where the free holes drive a ferromagnetic transition [2], and its presence in, e.g., EuS:Gd and EuO:Gd [27], in which a short range ferromagnetic interaction between the Eu spins dominates [28]. At the same time, it is expected that the suppression of the critical fluctuations will make it possible to probe directly the magnetic long range order by means of inter-or intraband magnetospectroscopy.…”

Section: Applicability Of the Mean-field Approximationmentioning

confidence: 99%

“…It has been known for a long time that the compensation of these interactions by a ferromagnetic coupling would result in a dramatic enhancement of the sensitivity of DMS to the temperature and to the magnetic field, particularly in the vicinity of the ferromagnetic phase transition. Search for the ferromagnetic transition has been successful in the case of Mn-based p-type IV-VI [2] and III-V compounds [3], in the latter case a critical temperature as high as 110 K has recently been reported for Ga 0.95 Mn 0.05 As [4,5]. In the case of II-VI DMS, a tight binding model [6] suggests that the superexchange in Cr-based DMS might be dominated by a ferromagnetic contribution.…”

Section: Introductionmentioning

confidence: 99%

Ferromagnetic Transition in Diluted Magnetic Semiconductors

Dietl¹

1999

Condens. Matter Phys.

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A summary is given of recent theoretical works on effects of the RudermanKittel-Kasuya-Yosida (RKKY) interaction between the localized spins in various dimensionality systems of doped diluted magnetic semiconductors (DMS). Since this interaction is long-range, its influence on the temperature and magnetic field dependencies of magnetization and spin splitting of the bands is evaluated in the mean field approximation, but by taking into consideration disorder-modified carrier-carrier interactions. Theoretical evaluations show that the hole densities, which can presently be achieved, are sufficiently high to drive a paramagneticferromagnetic phase transition in bulk and modulation-doped structures of II-VI DMS. The results of recent magnetooptical studies on MBE-grown samples, containing a single, modulation-doped, 8 nm quantum well of Cd 1−x Mn x Te/Cd 1−y−z Mg y Zn z Te:N are shown to corroborate the theoretical expectations. These studies reveal the presence of a ferromagnetic transition induced by the two-dimensional hole gas. The transition occurs between 1.8 and 2.5 K, depending on the Mn concentration x, in agreement with the theoretical model.

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Magnetic phase diagram of Pb1−−Sn Mn Te semimagnetic semiconductors

Cited by 50 publications

References 19 publications

IV-VI Semimagnetic Semiconductors: Recent Developments

IV-VI Semimagnetic Semiconductors: Recent Developments

Semiconductor Ferromagnetic Structures

Ferromagnetic Transition in Diluted Magnetic Semiconductors

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