The Experts below are selected from a list of 2958 Experts worldwide ranked by ideXlab platform

Cui Ding - One of the best experts on this subject based on the ideXlab platform.

K Ando - One of the best experts on this subject based on the ideXlab platform.

  • room temperature ferromagnetism in a ii vi Diluted Magnetic Semiconductor zn 1 x cr x te
    Physical Review Letters, 2003
    Co-Authors: H Saito, V Zayets, S Yamagata, K Ando
    Abstract:

    The Magnetic and magneto-optical properties of a Cr-doped II-VI Semiconductor ZnTe were investigated. Magnetic circular dichroism measurements showed a strong interaction between the $sp$ carriers and localized $d$ spins, indicating that ${\mathrm{Z}\mathrm{n}}_{1\ensuremath{-}x}{\mathrm{C}\mathrm{r}}_{x}\mathrm{T}\mathrm{e}$ is a Diluted Magnetic Semiconductor. The Curie temperature of the film with $x=0.20$ was estimated to be $300\ifmmode\pm\else\textpm\fi{}10\text{ }\mathrm{K}$, which is the highest value ever reported for a Diluted Magnetic Semiconductor in which $sp\mathrm{\text{\ensuremath{-}}}d$ interactions were confirmed. In spite of its high Curie temperature, ${\mathrm{Z}\mathrm{n}}_{1\ensuremath{-}x}{\mathrm{C}\mathrm{r}}_{x}\mathrm{T}\mathrm{e}$ film shows semiconducting electrical transport properties.

  • room temperature ferromagnetism in a ii vi Diluted Magnetic Semiconductor zn 1 x cr x te
    Physical Review Letters, 2003
    Co-Authors: H Saito, V Zayets, S Yamagata, K Ando
    Abstract:

    The Magnetic and magneto-optical properties of a Cr-doped II-VI Semiconductor ZnTe were investigated. Magnetic circular dichroism measurements showed a strong interaction between the sp carriers and localized d spins, indicating that Zn(1-x)Cr(x)Te is a Diluted Magnetic Semiconductor. The Curie temperature of the film with x=0.20 was estimated to be 300+/-10 K, which is the highest value ever reported for a Diluted Magnetic Semiconductor in which sp-d interactions were confirmed. In spite of its high Curie temperature, Zn(1-x)Cr(x)Te film shows semiconducting electrical transport properties.

  • ferromagnetism in ii vi Diluted Magnetic Semiconductor zn1 xcrxte
    Journal of Applied Physics, 2002
    Co-Authors: H Saito, S Yamagata, Wadim Zaets, Y Suzuki, K Ando
    Abstract:

    Magnetic and transport properties of an epitaxial film of ferroMagnetic II–VI Diluted Magnetic Semiconductor (DMS) Zn1−xCrxTe (x=0.035) were investigated. The Curie temperature TC of the film was about 15 K, which is the highest among the reported ferroMagnetic II–IV DMS. Hall effect measurements at room temperature showed a hole concentration p of about 1×1015 cm−3, which is several orders lower than that reported for carrier-induced ferroMagnetic Zn1−xMnxTe. These results suggest that a ferroMagnetic superexchange interaction between Cr ions is responsible for the observed ferromagnetism in Zn1−xCrxTe.

  • magneto optic effect of the ferroMagnetic Diluted Magnetic Semiconductor ga1 xmnxas
    Journal of Applied Physics, 1998
    Co-Authors: K Ando, T Hayashi, M Tanaka, A Twardowski
    Abstract:

    Magnetic circular dichroism (MCD) of a ferroMagnetic Diluted Magnetic Semiconductor Ga1−xMnxAs films was measured to clarify their electronic structure. Strong enhancement of MCD by Mn substitution indicated a strong sp–d hybridization. The p–d exchange interaction was concluded to be antiferroMagnetic, which was in contrast with the reported ferroMagnetic p–d exchange in very Diluted paraMagnetic GaAs:Mn bulk crystals. The change of the character of the p–d exchange interaction is due to the unique feature of Ga1−xMnxAs that the relative abundance of the neutral and ionized Mn acceptors controls the p–d exchange.

Bijuan Chen - One of the best experts on this subject based on the ideXlab platform.

  • hole doping and pressure effects on the ii ii v based Diluted Magnetic Semiconductor b a 1 x k x z n 1 y m n y 2 a s 2
    Physical Review B, 2017
    Co-Authors: Bijuan Chen, F Sun, G Q Zhao, Yonggang Wang, C A Escanhoela, Ronghui Kou, Yuming Xiao, Paul Chow, H K Mao
    Abstract:

    We investigate doping- and pressure-induced changes in the electronic state of Mn $3d$ and As $4p$ orbitals in II-II-V-based Diluted Magnetic Semiconductor $(\mathrm{B}{\mathrm{a}}_{1\ensuremath{-}x}{\mathrm{K}}_{x}){(\mathrm{Z}{\mathrm{n}}_{1\ensuremath{-}y}\mathrm{M}{\mathrm{n}}_{y})}_{2}\mathrm{A}{\mathrm{s}}_{2}$ to shed light into the mechanism of indirect exchange interactions leading to high ferroMagnetic ordering temperature ($T\mathrm{c}=230\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ in optimally doped samples). A suite of x-ray spectroscopy experiments (emission, absorption, and dichroism) show that the emergence and further enhancement of ferroMagnetic interactions with increased hole doping into the As $4p$ band is accompanied by a decrease in local $3d$ spin density at Mn sites. This is a result of increasing Mn $3d--\mathrm{As} 4p$ hybridization with hole doping, which enhances indirect exchange interactions between Mn dopants and gives rise to induced Magnetic polarization in As $4p$ states. On the contrary, application of pressure suppresses exchange interactions. While Mn K $\ensuremath{\beta}$ emission spectra show a weak response of $3d$ states to pressure, clear As $4p$ band broadening (hole delocalization) is observed under pressure, ultimately leading to loss of ferromagnetism concomitant with a Semiconductor to metal transition. The pressure response of As $4p$ and Mn $3d$ states is intimately connected with the evolution of the As-As interlayer distance and the geometry of the $\mathrm{MnA}{\mathrm{s}}_{4}$ tetrahedral units, which we probed with x-ray diffraction. Our results indicate that hole doping increases the degree of covalency between the anion (As) $p$ states and cation (Mn) $d$ states in the $\mathrm{MnA}{\mathrm{s}}_{4}$ tetrahedron, a crucial ingredient to promote indirect exchange interactions between Mn dopants and high $T\mathrm{c}$ ferromagnetism. The instability of ferromagnetism and semiconducting states against pressure is mainly dictated by delocalization of anion $p$ states.

  • li zn co mn as a bulk form Diluted Magnetic Semiconductor with co and mn co doping at zn sites
    AIP Advances, 2016
    Co-Authors: Bijuan Chen, Zheng Deng, Moran Gao, Qingqing Liu, Guoqiang Zhao, Jianfa Zhao, Xiancheng Wang, Changqing Jin
    Abstract:

    We report the synthesis and characterization of a series of bulk forms of Diluted Magnetic Semiconductors Li(Zn1-x-yCoxMny)As with a crystal structure close to that of III-V Diluted Magnetic Semiconductor (Ga,Mn)As. No ferroMagnetic order occurs with single (Zn,Co) or (Zn, Mn) substitution in the parent compound LiZnAs. Only with co-doped Co and Mn ferroMagnetic ordering can occur at the Curie temperature ∼40 K. The maximum saturation moment of the this system reached to 2.17μB/Mn, which is comparable to that of Li (Zn,Mn)As. It is the first time that a Diluted Magnetic Semiconductor with co-doping Co and Mn into Zn sites is achieved in “111” LiZnAs system, which could be utilized to investigate the basic science of ferromagnetism in Diluted Magnetic Semiconductors. In addition, ferroMagnetic Li(Zn,Co,Mn)As, antiferroMagnetic LiMnAs, and superconducting LiFeAs share square lattice at As layers, which may enable the development of novel heterojunction devices in the future.

  • new fluoride arsenide Diluted Magnetic Semiconductor ba k f zn mn as with independent spin and charge doping
    Scientific Reports, 2016
    Co-Authors: Bijuan Chen, Zheng Deng, Moran Gao, Qingqing Liu, B G Shen, Benjamin A Frandsen, Sky C Cheung, Liu Lian, Y J Uemura, Cui Ding
    Abstract:

    New Fluoride-arsenide Diluted Magnetic Semiconductor (Ba,K)F(Zn,Mn)As with Independent Spin and Charge Doping

  • new fluoride arsenide Diluted Magnetic Semiconductor ba k f zn mn as with independent spin and charge doping
    Scientific Reports, 2016
    Co-Authors: Bijuan Chen, Zheng Deng, Moran Gao, Qingqing Liu, B G Shen, Benjamin A Frandsen, Sky C Cheung, Liu Lian, Y J Uemura, Cui Ding
    Abstract:

    We report the discovery of a new fluoride-arsenide bulk Diluted Magnetic Semiconductor (Ba,K)F(Zn,Mn)As with the tetragonal ZrCuSiAs-type structure which is identical to that of the “1111” iron-based superconductors. The joint hole doping via (Ba,K) substitution & spin doping via (Zn,Mn) substitution results in ferroMagnetic order with Curie temperature up to 30 K and demonstrates that the ferroMagnetic interactions between the localized spins are mediated by the carriers. Muon spin relaxation measurements confirm the intrinsic nature of the long range Magnetic order in the entire volume in the ferroMagnetic phase. This is the first time that a Diluted Magnetic Semiconductor with decoupled spin and charge doping is achieved in a fluoride compound. Comparing to the isostructure oxide counterpart of LaOZnSb, the fluoride DMS (Ba,K)F(Zn,Mn)As shows much improved semiconductive behavior that would be benefit for further application developments.

  • pressure effect on the magnetism of the Diluted Magnetic Semiconductor b a 1 x k x z n 1 y m n y 2 a s 2 with independent spin and charge doping
    Physical Review B, 2016
    Co-Authors: Bijuan Chen, F Sun, Ying Jia, L J Zhang, G Q Zhao, L Y Xing, Gilberto Fabbris, Yonggang Wang
    Abstract:

    We used x-ray Magnetic circular dichroism (XMCD) to probe the ferroMagnetic properties of As $p$-symmetric ($4p$) states in the recently synthesized Diluted Magnetic Semiconductor $(\mathrm{B}{\mathrm{a}}_{1\ensuremath{-}x}{\mathrm{K}}_{x}){(\mathrm{Z}{\mathrm{n}}_{1\ensuremath{-}y}\mathrm{M}{\mathrm{n}}_{y})}_{2}\mathrm{A}{\mathrm{s}}_{2}$ system under ambient- and high-pressure conditions. The As $K$-edge XMCD signal scales with the sample magnetization (dominated by Mn) and scales with the ferroMagnetic ordering temperature $T\mathrm{c}$, and hence it is representative of the bulk magnetization. The XMCD intensity gradually decreases upon compression and vanishes at around 25 GPa, indicating quenching of ferromagnetism at this pressure. Transport measurements show a concomitant increase in conductivity with pressure, leading to a nearly metallic state at about the same pressure where Magnetic order collapses. High-pressure x-ray diffraction shows an absence of structural transitions to 40 GPa. The results indicate that the mobility of doped holes, probed by both transport and x-ray absorption spectroscopy ($4p$ band broadening), is intimately connected with the mechanism of Magnetic ordering in this class of compounds and that its control using external pressure provides an alternative route for tuning the Magnetic properties in Diluted Magnetic Semiconductor materials.

F L Ning - One of the best experts on this subject based on the ideXlab platform.

Huiyuan Man - One of the best experts on this subject based on the ideXlab platform.

  • ba1 xkx cu2 xmnx se2 a copper based bulk form Diluted Magnetic Semiconductor with orthorhombic bacu2s2 type structure
    Journal of Magnetism and Magnetic Materials, 2016
    Co-Authors: Shengli Guo, Cui Ding, Huiyuan Man, Xin Gong, Yao Zhao, Bin Chen, Yang Guo, Hangdong Wang, F L Ning
    Abstract:

    Abstract A new copper-based bulk form Diluted Magnetic Semiconductor (DMS) (Ba 1− x K x )(Cu 2− x Mn x )Se 2 ( x =0.075, 0.10, 0.125, and 0.15) with T C ∼18 K has been synthesized. K substitution for Ba introduces hole-type carriers, while Mn substitution for Cu provides local spins. Different from previous reported DMSs, this material crystallizes into orthorhombic BaCu 2 S 2 -type crystal structure. No ferromagnetism is observed when only doping Mn, and clear ferroMagnetic transition and hysteresis loop have been observed as K and Mn are codoped into the parent compound BaCu 2 Se 2 .

  • sr3la2o5 zn1 xmnx 2as2 a bulk form Diluted Magnetic Semiconductor isostructural to the 32522 fe based superconductors
    arXiv: Strongly Correlated Electrons, 2014
    Co-Authors: Huiyuan Man, Cui Ding, Shengli Guo, Xin Gong, Bin Chen, Hangdong Wang, Chuan Qin, Quan Wang, F L Ning
    Abstract:

    A new Diluted Magnetic Semiconductor system, (Sr3La2O5)(Zn1-xMnx)2As2, has been synthesized and characterized. 10% Mn substitution for Zn in bulk form (Sr3La2O5)Zn2As2 results in a ferroMagnetic ordering below Curie temperature, TC ~ 40 K. (Sr3La2O5)(Zn1-xMnx)2As2 has a layered crystal structure identical to that of 32522-type Fe based superconductors, and represents the fifth DMS family that has a direct counterpart among the FeAs high temperature superconductor families.

  • sr3la2o5 zn1 xmnx 2as2 a bulk form Diluted Magnetic Semiconductor isostructural to the 32522 fe based superconductors
    EPL, 2014
    Co-Authors: Huiyuan Man, Cui Ding, Shengli Guo, Xin Gong, Bin Chen, Hangdong Wang, Chuan Qin, Quan Wang, F L Ning
    Abstract:

    A new Diluted Magnetic Semiconductor (DMS) system, (Sr3La2O5)(Zn1−xMnx)2As2, has been synthesized and characterized. 10% Mn substitution for Zn in bulk form (Sr3La2O5)Zn2As2 results in a ferroMagnetic ordering below the Curie temperature, . (Sr3La2O5)(Zn1−xMnx)2As2 has a layered crystal structure identical to that of 32522-type Fe-based superconductors, and represents the fifth DMS family that has a direct counterpart among the FeAs high-temperature superconductor families.

  • la 1 x ba x zn 1 x mn x aso a two dimensional 1111 type Diluted Magnetic Semiconductor in bulk form
    Physical Review B, 2013
    Co-Authors: Cui Ding, Chunmu Feng, Huiyuan Man, Yunlei Sun, Chuan Qin, Quan Wang, T Goko, C Arguello, Lian Liu, Benjamin A Frandsen
    Abstract:

    We report the synthesis and characterization of a bulk Diluted Magnetic Semiconductor (La1-xBax)(Zn1-xMnx)AsO (0 <= x <= 0.2) with a layered crystal structure identical to that of the 1111-type FeAs superconductors. No ferroMagnetic order occurs with (Zn,Mn) substitution in the parent compound LaZnAsO without charge doping. Together with carrier doping via (La,Ba) substitution, a small amount of Mn substituting for Zn results in ferroMagnetic order with T-C up to similar to 40 K, although the system remains semiconducting. Muon spin relaxation measurements confirm the development of ferroMagnetic order in the entire volume, with the relationship between the internal field and TC consistent with the trend found in (Ga,Mn) As and the 111-type Li(Zn,Mn) As and the 122-type (Ba,K)(Zn,Mn)(2)As-2 systems.

  • la 1 x ba x zn 1 x mn x aso a two dimensional 1111 type Diluted Magnetic Semiconductor in bulk form
    Physical Review B, 2013
    Co-Authors: Cui Ding, Chunmu Feng, Huiyuan Man, Yunlei Sun, Chuan Qin, Quan Wang, T Goko, C Arguello, Li Liu, Benjamin A Frandsen
    Abstract:

    We report the synthesis and characterization of a bulk Diluted Magnetic Semiconductor (La${}_{1\ensuremath{-}x}$Ba${}_{x}$)(Zn${}_{1\ensuremath{-}x}$Mn${}_{x}$)AsO (0 $\ensuremath{\leqslant}$ $x$ $\ensuremath{\leqslant}$ 0.2) with a layered crystal structure identical to that of the 1111-type FeAs superconductors. No ferroMagnetic order occurs with (Zn,Mn) substitution in the parent compound LaZnAsO without charge doping. Together with carrier doping via (La,Ba) substitution, a small amount of Mn substituting for Zn results in ferroMagnetic order with ${T}_{C}$ up to $\ensuremath{\sim}$40 K, although the system remains semiconducting. Muon spin relaxation measurements confirm the development of ferroMagnetic order in the entire volume, with the relationship between the internal field and ${T}_{C}$ consistent with the trend found in (Ga,Mn)As and the 111-type Li(Zn,Mn)As and the 122-type (Ba,K)(Zn,Mn)${}_{2}$As${}_{2}$ systems.