scholarly journals A CaAl 2 Si 2 -Type Magnetic Semiconductor (Sr, Na)(Zn, Mn)2Sb2 Isostructural to 122-Type Iron-Based Superconductors

2022 ◽  
Vol 2022 ◽  
pp. 1-7
Yilun Gu ◽  
Rufei Zhang ◽  
Haojie Zhang ◽  
Licheng Fu ◽  
Guoxiang Zhi ◽  

A new diluted magnetic semiconductor (Sr, Na)(Zn, Mn)2Sb2 has been successfully synthesized by doping Na and Mn into the parent compound SrZn 2 Sb 2 , which has a CaAl 2 Si 2 -type crystal structure (space group P 3 ¯ m 1 , No. 164, h P 5 ) isostructural to the 122-type iron-based superconductor CaFe 2 As 2 . No magnetic ordering has been observed when only spins are doped by (Zn, Mn) substitution. Only with carriers codoped by (Sr, Na) substitution, a ferromagnetic ordering occurs below the maximum Curie temperature T C ∼9.5 K. Comparing with other CaAl 2 Si 2 -type diluted magnetic semiconductors, we will show that negative chemical pressure suppresses the Curie temperature.

2010 ◽  
Vol 168-169 ◽  
pp. 376-379
E.A. Zvereva ◽  
O.A. Savelieva ◽  
S. Ibragimov ◽  
Y. Titov ◽  
E.I. Slynko ◽  

We have studied the magnetic susceptibility, magnetization and electron paramagnetic resonance (EPR) in the diluted magnetic semiconductor Pb1-x-yMgxYbyTe. The magnetic susceptibility of this system is a superposition of the matrix diamagnetism, the paramagnetic contribution of electrons localized in the ytterbium band, and the Curie-Weiss paramagnetism provided by Yb3+ ions. The concentration of Yb3+ ions monotonically increases with the ytterbium content, while a significant fraction of ytterbium ions remains in a nonmagnetic Yb2+ state. A pronounced hyperfine structure was revealed in the EPR spectra. It was ascribed to the interaction between the electron magnetic moment of an unfilled electron shell of Yb3+ ions and nuclear magnetic moment of the 173Yb isotope. The estimated values of the effective g-factor (g1.997 0.002) and the hyperfine-interaction constant (173A=0,56 cm-1) were found to be almost independent of both alloy composition and temperature.

2008 ◽  
Vol 1119 ◽  
A Ghosh ◽  
R K Gupta ◽  
P K Kahol ◽  
K Ghosh

AbstractThin films of Co-doped In2O3 diluted magnetic semiconductor have been grown on c-plane sapphire single crystals using pulsed laser deposition technique. Different characterizations such as x-ray diffraction, atomic force microscopy, and magneto-transport have been carried out to study the effect of growth temperature on structural, electrical, and magneto-transport properties of these films. Crystalinity of the films increases with the growth temperature. The films grown at high temperature have preferred orientation along (222) direction, while films grown at low temperature behave more like to nanocrystaline. It is observed that electrical properties of the films strongly depend on growth temperature. The resistivity and magnetoresistance of the films decreases with increase in growth temperature. On the other hand, mobility of the films increases with increase in growth temperature. This could be due to improvement in crystalinity of the films.

2008 ◽  
Vol 591-593 ◽  
pp. 387-391
Lucianna Gama ◽  
M.A. Ribeiro ◽  
Débora A. Vieira ◽  
A.M.C. Santos ◽  
Ruth Herta Goldsmith Aliaga Kiminami ◽  

Diluted magnetic semiconductors (DMS), which have both semiconducting and magnetic properties, are those in which transitions metal ions substitute cations of host semiconductor materials [1]. There is a great interest for DMS for use as the material of spintronics. In this study is reported the structural and morphologic characterization of Zn1.95Co0.05O nanoparticles obtained by Pechini method and combustion reaction. The powders resulting were characterized by X-ray diffraction (XRD) for determination of the phases, crystalline phase and lattice parameter; nitrogen adsorption by BET for determination of the specific superficial area and calculation the particle size from the superficial area and scanning electron microscopy (SEM) for morphologic analysis. The XRD results demonstrated the viability of obtaining crystalline and nanosize powders by the both synthesis routes. For all samples the average crystallite sizes was nanosized, but the powders obtained by reaction combustion is smaller. The SEM micrographs shows that the powders obtained for both syntheses are constituted of soft agglomerates.

2001 ◽  
Vol 700 ◽  
T. Fukumura ◽  
M. Kawasaki ◽  
Zhengwu Jin ◽  
H. Kimura ◽  
Y. Yamada ◽  

AbstractDiluted magnetic semiconductor (DMS) possesses charge and spin degrees of freedom leading to their interplay promising for novel devices. DMSs based on II-VI and III-V compound semiconductors have been extensively studied so far. Recently, the oxide semiconductors doped with transition metal magnetic impurity have attracted much attention for the possible high ferromagnetic Curie temperature. Here, we overview recent studies of the transparent oxide based DMSs, ZnO, TiO2, and SnO2 doped with 3d transition metals, by using the combinatorial materials synthesis and the high throughput screening.

2018 ◽  
Vol 185 ◽  
pp. 06001
Vasilii S. Zakhvalinskii ◽  
Tatyana B. Nikulicheva ◽  
Erkki Lähderanta ◽  
Aleksey V. Kochura ◽  
Ekaterina A. Nikitovskaia ◽  

Single crystals of a diluted magnetic semiconductor (Cd1-x-yZnxMny)3As2 (CZMA) (x + y = 0.4;y=0.04 and 0.08) obtained by Bridgman method were used. The Shubnikov-de Haas (SdH) effect was observed within studying of the dependence of the resistivity on the magnetic field in CZMA solid solutions. The values of the cyclotron mass mc, Hall and Shubnikov carrier concentrations were calculated.

1986 ◽  
Vol 89 ◽  
Jacek Kossut ◽  
Jacek K. Furdyna

AbstractThe presence of transition metal ions (typically Mn2+) in diluted magnetic semiconductors (DMS) results in a strong spin-spin coupling between localized magnetic moments and band electrons. This leads to considerable modifications of the semiconductor band structure in the presence of strong magnetic fields, e.g., to large spin-dependent shifts of the electronic states at the band edge. This feature is of particular interest in the context of quantum wells involving DMS. Starting with the original idea of a “spin-superlattice”, we concentrate on various opportunities which arise due to the tunability of the depth of the quantum wells by the magnetic field and/or temperature associated with the aforementioned spindependent effects. Thus, we discuss boil-off and freeze-out of electrons to and from quantum wells, selective spin tunneling across the barriers, tunable infrared emitters, enhancement of electronic g-factors in shallow non-magnetic wells surrounded by DMS barriers, the possibility of transition from a type-1 to a type-il superlattice induced by the magnetic field, and quantum oscillations anomalies in DMS quantum wells.

NANO ◽  
2008 ◽  
Vol 03 (01) ◽  
pp. 1-19 ◽  

An idea for simultaneously manipulating spin and charge in a single semiconductor medium has resulted in the development of diluted magnetic semiconductors (DMSs), which exhibits surprisingly room temperature ferromagnetic signatures despite having controversial ferromagnetic origin. However, achievement of truly room temperature ferromagnetism by carrier mediation is still the subject of intense research to develop the practical spin-based devices. Nanowires with one-dimensional nanostructure, which offers thermodynamically stable features and typically single crystalline and defect free, have a number of advantages over thin films with respect to studying ferromagnetism in DMSs. This review focuses primarily on our works on GaN -based DMS nanowires, i.e., Mn -doped GaN , Mn -doped AlGaN and Cu -doped GaN nanowires. These DMS nanowires have room temperature ferromagnetism by the local magnetic moment of doping elements that are in a divalent state and in tetrahedral coordination, thus substituting Ga in the wurtzite-type network structure of host materials. Importantly, our evidences indicate that the magnetism is originated from the ferromagnetic interaction driven by the carrier. These outcomes suggest that nanowires are ideal building blocks to address the magnetism in DMS due to their thermodynamic stability, single crystallinity, free of defects and free standing nature from substrate. Nanowires themselves are ideal building blocks for nanodevices and, thus, it would also be helpful in developing DMS-based spin devices.

1989 ◽  
Vol 151 ◽  
B. T. Jonker ◽  
J. J. Krebs ◽  
G. A. Prinz ◽  
X. Liu ◽  
A. Petrou ◽  

ABSTRACTWe have grown single crystal zincblende epilayers of the diluted magnetic semiconductors Zn1−xFexSe and Zn1−xCoxSe on GaAs(001) by molecular beam epitaxy. We summarize the growth and the structural, magnetic and optical properties of these materials, and contrast their properties with those of the more well-studied Mn-based family of diluted magnetic semiconductor (DMS) compounds. Both materials exhibit larger values for the band electronmagnetic ion and ion-ion exchange parameters than found in (Zn,Mn)Se. These values are most strongly enhanced in (Zn,Co)Se, which represents the first member of a new Co-based family of DMS compounds. Thus the incorporation of (Zn,Fe)Se and (Zn,Co)Se layers in quantum well and superlattice structures holds very exciting prospects for future work.

2013 ◽  
Vol 652-654 ◽  
pp. 585-589 ◽  
Tong Li ◽  
Qiong Jie ◽  
Yu Zhang ◽  
Ya Xin Wang ◽  
Xiao Chang Ni

The discovery of ferromagnetism (FM) in wide band-gap semiconductors doped with transition metals (TM), known as diluted magnetic semiconductors (DMSs), has attracted much interest. These materials are applicable to spin-based optoelectronic devices working at room temperature (RT). Among DMSs, the system of Co-doped ZnO is considered as the most promising candidate, which was expected to robust magnetism. This paper focuses primarily on the recent progress in the experimental studies of ZnO:Co DMSs. The magnetic properties and possible mechanism of ZnO:Co DMSs prepared by different methods are summarized and reviewed.

2021 ◽  
Anielle C.A. Silva ◽  
Amanda I.S. Barbosa ◽  
Alessandra S. Silva ◽  
Elisson A. Batista ◽  
Thaís K. de Lima Rezende ◽  

Diluted Magnetic Semiconductor (DMS) nanocrystals are a new class of materials formed by doping the semiconductor with transition metals (TM), which gives interesting magneto-optical properties. These properties are attributed to the exchange interaction between the pure semiconductor’s sp-electrons and the localized TM d-electrons. This book chapter shows exciting results of new DMS developed by the group, both in powder form and embedded in glassy systems. Depending on the concentration of doping ions, saturation of the incorporation of substitutional and interstitial sites in the nanocrystal structure may occur, forming other nanocrystals. In this context, we investigated the doping saturation limit in nanopowders of DMS Zn1-xMnxO NCs and Zn1-xMnxTe, Zn0.99-xMn0.01CoxTe, and Bi2-xCoxS NCs synthesized in glassy matrices. Thus, the sites’ saturation into the crystalline lattice of nanocrystals is a topic little reported in the literature, and we will comment on this work. Therefore, we will show results from the group about the modulation and saturation in diluted magnetic semiconductors nanocrystals in this work.

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