Showing papers on "Magnetic semiconductor published in 1983"
TL;DR: In this article, the authors considered the magnetic field and temperature dependences of spin splitting for an electron localized on a shallow donor, taking into account the $s\ensuremath{-}d$ coupling with the surrounding magnetic ions.
Abstract: We consider the magnetic field and temperature dependences of the spin splitting for an electron localized on a shallow donor, taking into account the $s\ensuremath{-}d$ coupling with the surrounding magnetic ions. We calculate the probability distribution of the spin splitting $\ensuremath{\Delta}$ with the thermodynamic fluctuations of magnetization included. They are responsible for persistence of the spin splitting at ambient temperature in the absence of the field. The probability distribution of the spin splitting is the main factor determining the energy and the shape of the optical transition line between the spin-split states. We compare our results with recent experimental results on spin-flip Raman scattering in ${\mathrm{Cd}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{Se}$. Our theory provides a satisfactory quantitative description of the donor electron accompanied by a nonuniform cloud of magnetization in that material.
104 citations
46 citations
38 citations
TL;DR: The magnetic properties of melt-spun iron-zirconium alloys are drastically altered by the addition of hydrogen as discussed by the authors, which increases both the Curie temperature and the moment per iron atom, from 252K and 1.6 mu B, respectively, to 382K and 2.0 mu B.
Abstract: The magnetic properties of melt-spun iron-zirconium alloys are drastically altered by the addition of hydrogen. The transformation of the magnetic order in Fe89Zr11 from collinear ferromagnetism to asperomagnetism below 60 K is suppressed in Fe89Zr11H20, which remains ferromagnetic at all temperatures. Hydrogenation increases both the Curie temperature and the moment per iron atom, from 252K and 1.6 mu B, respectively, to 382K and 2.0 mu B.
38 citations
TL;DR: The magnetic phase diagram of amorphous FexNi78−xSi9B13 in the concentration range up to x = 9 has been obtained by the 57Fe Mossbauer effect as discussed by the authors.
29 citations
TL;DR: In this paper, the spin-glass behavior of diluted magnetic semiconductors was investigated and attributed to the frustration inherent in the hcp lattices of these compounds, and phase diagrams for the boundary of the paramagnetic and the spinglass phases were presented for the two alloy systems, and the difference between the two phase diagrams was discussed.
22 citations
17 citations
TL;DR: In this paper, the two approaches to understand the magnetic properties of materials are the localized Heisenberg model and the band theory of electrons, and it is found that measurements near and above the Curie temperature are particulary useful for distinguishing between models for ferromagnetism in these materials.
10 citations
TL;DR: In this article, the characterization of properties and application prospects for ternary magnetic semiconductors (TMS) are reviewed, and the regulation of the TMS properties can be achieved either by composition change while growing crystals or by further thermal treatment.
Abstract: Crystal growth processes, the characterization of properties and the application prospects for ternary magnetic semiconductors (TMS) are reviewed. The regulation of the TMS properties can be achieved either by composition change while growing crystals or by further thermal treatment. The compounds CdCr2Se4, CdCr2S4, Cu
y
Cr2Se4−z
Br
x
have been selected for discussion.
9 citations
TL;DR: In this paper, microwave Faraday rotation was used to determine the magnetic susceptibility of diluted magnetic semiconductor Cd 1− x Mn x Te (0.17 x -12 s), and resonance shifts equivalent g -factor changes from 2.0 to 5.0 are observed.
8 citations
30 Nov 1983
TL;DR: In this paper, the properties of Hgl-xMnxTe have been examined and compared with those of Hg l-xCdxTe and Hg cdxTe in terms of electrical and optical properties.
Abstract: The band structure as well as electrical and optical properties of Hgl-xMnxTe are remarkably similar to those of Hg l-xCdxTe, making Hgl-xMnxTe a competitive candidate for applications in infrared detectors. In this paper we examine the properties of Hg1-xMnxTe which are relevant to this application. Hgl-xMnxTe is formed by substitution of tie magnetic Mn ions for Hg in the HgTe lattice; although Mn is not a group II element, Hgl-xMnxTe crystallizes in the zincblende structure, forming good quality crystals up to x 0.3S. Its energy gap and related band parameters vary with x, but at a rate about twice as fast as in Hgl-xCdxTe. The electrical properties of Hg1-xMnxTe are again similar to those of Hgl-xCdxTe, including electronic mobilities and doping characteristics. As-grown Hgl-x MnxTe is p-type due to a natural tendency to form Hg-vacancies, which act as acceptors and whose concentration can be reduced by appropriate annealing. Because Mn is a magnetic ion, Hg l- differs from Hgl-xCdxTe in its magnetic properties, as well as in the behavior of its electrical and optical properties in the presence of a magnetic field. For example, for x > 0.17 Hg1-xMnxTe exhibits a transition to the spin glass phase at low temperatures. Furthermore, the presence of Mn ions leads to an exchange interaction between the localized magnetic moments and the band electrons, which in turn affects the band parameters and leads to new and spectacular effects in the transport and optical properties. It is to be emphasized that magnetic properties associated with the Mn ions, such as electron paramagnetic resonance, magnetic susceptibility, etc., also offer a unique handle by which the distribution of Mn over the lattice (e.g., its tendency to form clusters) can be studied.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
TL;DR: In this paper, the magnon scattering by free carriers in the simultaneous presence of two laser fields is considered, and a kinetic equation for magnon population is derived, which is foubd that spin waves propagating parallel to the direction of polarization of the fields may be amplified over a relatively narrow band of magnon wavenumbers.
TL;DR: In this article, low-temperature measurements of ferromagnetic resonance in CdCr2S4 crystals demonstrated the coexistence of chromium ions with minority valence 2+ and 4+.
Abstract: Low-temperature measurements of ferromagnetic resonance in CdCr2S4 crystals demonstrated the coexistence of chromium ions with minority valence 2+ and 4+.
TL;DR: In this article, the photoconductivity of the magnetic semiconductor compound Cd1−x Mn x Se has been studied at 300 K and at 77K for several Bridgman-grown single crystals.
Abstract: The photoconductivity of the magnetic semiconductor compound Cd1−x Mn x Se has been studied at 300 K and at 77K for the first time for several Bridgman-grown single crystals. With this technique it was possible to detect the Mn 3d level. Experimental data found in this investigation reveal that the Mn 3d level is pinned at 1.9 eV below the bottom of the conduction band,i.e. it is independent of temperature and insensitive to the amount of manganese.
01 Jan 1983
TL;DR: In this paper, the authors present new results obtained from ESR experiments in the paramagnetic and magnetic ordered states of both crystallographic phases of the magnetic semiconductor GaCr4S8.
Abstract: We present new results obtained from ESR experiments in the paramagnetic and magnetic ordered states of both crystallographic phases of the magnetic semiconductor GaCr4S8. We observe a critical behaviour typical of magnetic phase transitions, resulting in a shift and a broadening of the resonance line as well as a distortion of its shape. These features are discussed and related to the presence of magnetization fluctuations. J. Physique - LETTRES 44 (1983) L-393 - L-401
TL;DR: In this article, a method which employs an rf oscillator to determine the Curie temperature and magnetization of ferromagnetic materials has been described, and the results obtained on some intermetallic compounds viz. CrTe, Mn1.1Sb, Mn 1.2Sb and Mn 0.9Fe 0.
Journal Article•
TL;DR: In this paper, the first calculation of the electron structure of the magnetic spinel semiconductor CdCr2Se4 by means of the atomic sphere approximation method was made by making use of the spinel lattice.
Abstract: In this paper we have made the first calculation of the electron structure of the magnetic spinel semiconductor CdCr2Se4 by means of the atomic sphere approximation method [1].
TL;DR: In this article, the temperature dependence of the known 2.0 eV and 1.2 eV PL bands is discussed in terms of a configuration coordinate model involving Mn2+ intra-ion transitions.
Abstract: Photoluminescence excitation measurements have been carried out on the diluted magnetic semiconductors Cd1−xMnxTe and Cd1−xMnxSe. The temperature dependence of the known 2.0 eV and 1.2 eV PL bands is discussed in terms of a configuration coordinate model involving Mn2+ intra-ion transitions. Two broad band emissions in Cd1−xMnxSe, at 2.13 eV and 1.35 eV, are reported which appear to be the analogies to the PL bands seen in Cd1−xMnxTe.
TL;DR: In this paper, the magnetic-field dependence of electron mobility and photoconductivity in semi-magnetic semiconductors has been studied both theoretically and experimentally and the electron relaxation times due to various scattering mechanisms are calculated paying special attention to spin disorder and alloy scatterings.
Abstract: Magnetic-field dependence of electron mobility and photoconductivity in semi-magnetic semiconductors are studied both theoretically and experimentally. The electron relaxation times due to various scattering mechanisms are calculated paying special attention to spin disorder and alloy scatterings. The calculated mobility in Cd1−c Mn c Te is compared with experimental photomagnetoresistance (PMR) results. It is concluded that the magnetic-field-dependent mobility may contribute significantly to PMR at high Mn concentrations and low temperatures.
TL;DR: In this paper, the effect of the electron-phonon interaction on the magnetic properties of an itinerant electron ferromagnet was investigated and it was shown that the electronphon interaction can make the paramagnetic spin susceptibility Curie-Weiss like, with a Curie temperature much lower than in the Stoner theory.