A5010951113- Iron-based superconductors research
- Magnetic and transport properties of perovskites and related materials
- ZnO doping and properties
- Rare-earth and actinide compounds
- Physics of Superconductivity and Magnetism
- Advanced Condensed Matter Physics
- Semiconductor materials and interfaces
- Inorganic Chemistry and Materials
- Chalcogenide Semiconductor Thin Films
- Magnetic properties of thin films
- Superconductivity in MgB2 and Alloys
- Corporate Taxation and Avoidance
- Semiconductor materials and devices
Zhejiang University
2016-2025
Zhejiang University of Technology
2021-2023
Collaborative Innovation Center of Advanced Microstructures
2016
Iron-chalcogenide superconductors FeSe 1− x S possess unique electronic properties such as nonmagnetic nematic order and its quantum critical point. The nature of superconductivity with nematicity is important for understanding the mechanism unconventional superconductivity. A recent theory suggested possible emergence a fundamentally new class so-called Bogoliubov Fermi surfaces (BFSs) in this system. However, an ultranodal pair state requires broken time-reversal symmetry (TRS)...
We report the manipulation of ferromagnetism in n-type magnetic semiconductor Ba(Zn,Co)2As2 through carriers' doping. Doping In or Cu into Zn-sites introduces additional p-type carriers, respectively. Focusing on Ba(Zn0.97Co0.03)2As2 which has a [Formula: see text] ∼ 31 K, doping carriers and 2% drastically improves ferromagnetic transition temperature by 16% to 36 K. contrast, 1.5% suppresses 52% 15 K; 3% turns dominant carrier p-type, eventually transforms ordering paramagnetic state. Our...
Diluted ferromagnetic semiconductors (DMSs) that combine the properties of with ferromagnetism have potential application in spin-sensitive electronics (spintronics) devices. The search for DMS materials exploded after observation ordering III-V (Ga,Mn)As films. Recently, a series compounds isostructural to iron-based superconductors been reported. Among them, highest Curie temperature $T_C$ 230 K has achieved (Ba,K)(Zn,Mn)$_2$As$_2$. However, most DMSs, including (Ga,Mn)As, are p-type,...
We explore the magnetically-ordered ground state of isovalently-substituted Mott-insulator Y$_{1-x}$La$_{x}$TiO$_{3}$ for $x$ $\leq$ 0.3 via single crystal growth, magnetometry, neutron diffraction, x-ray magnetic circular dichroism (XMCD), muon spin rotation ($\mu$SR) and small-angle scattering (SANS). find that decrease in transition temperature on approaching ferromagnetic (FM) - antiferromagnetic (AFM) phase boundary at La concentration $x_c$ $\approx$ is accompanied by a strong...
Abstract We report the successful synthesis and characterization of a novel 1111-type magnetic semiconductor (Ba 1− x Na )F(Zn Mn )Sb (0.05 ≤ 0.175) with tetragonal ZrSiCuAs-type structure, which is isostructural to layered iron-based superconductor La(O,F)FeAs. substitutions for Ba Zn introduce carriers local moments, respectively. Ferromagnetic interaction formed when are codoped, demonstrating that moments mediated by carriers. Iso-thermal magnetization shows coercive field as large ~ 12...
We report the effect of chemical pressure on ferromagnetic ordering recently reported n-type diluted magnetic semiconductor Ba(Zn[Formula: see text]Co[Formula: text])[Formula: text]As[Formula: text] which has a maximum [Formula: 45 K. Doping Sb into As-site and Sr Ba-site induces negative positive pressure, respectively. While conserving tetragonal crystal structure carriers, unit cell volume shrink by 0.3[Formula: with 15[Formula: doping, but drastically increase transition temperature...
Abstract Diluted magnetic semiconductors (DMSs) that possess both properties of and ferromagnetism, have attracted a lot attentions due to its potential applications for spin-sensitive electronic devices. Recently, series bulk form DMSs isostructural iron-based superconductors been reported, which can be readily investigated by microscopic experimental techniques such as nuclear resonance (NMR) muon spin rotation ( μ SR). The measurements demonstrated homogeneous ferromagnetism is achieved...
We report the synthesis and characterization of a bulk form diluted magnetic semiconductor, (La(1-x)Ca(x))(Zn(1-y) Mn(y))AsO, with layered crystal structure isostructural to that 1 type Fe-based high-temperature superconductor LaFeAsO antiferromagnetic LaMnAsO. With Ca Mn codoping into LaZnAsO, ferromagnetic ordering occurs below Curie temperature T(c) ∼30 K. Taking advantage decoupled charge spin doping, we investigate influence carrier concentration on state. For fixed 10%, increases from...
Abstract We have successfully synthesized a novel diluted magnetic semiconductor (Ca 1−2 x K 2 )(Zn 1− Mn ) As with decoupled charge and spin doping. The substitutions of 2+ , + (Zn in the parent compound CaZn (space group P m 1 (No. 164)) introduce carriers moments, respectively. Doping only into does not induce any type long range ordering. ferromagnetic ordering arise can when are simultaneously doped. resulted maximum Curie temperature reaches ~7 K, corresponding coercive field is ~60...
We report the successful synthesis and characterization of a new type I-II-V bulk form diluted magnetic semiconductor (DMS) Li(Zn,Mn,Cu)As, in which charge spin doping are decoupled via (Cu,Zn) (Mn,Zn) substitution at same Zn sites. Ferromagnetic transition temperature up to ∼33 K has been observed with coercive field ∼40 Oe for 12.5% level. μSR measurements confirmed that volume fraction reaches nearly 100% 2 K, mechanism responsible ferromagnetic interaction this system is as other DMSs.
We report the successful synthesis and characterization of a new layered diluted magnetic semiconductor (DMS) La(Zn,Mn,Cu)AsO which is isostructural to Fe-based "1111" superconductor. Mn Cu are codoped into same Zn sites provide local moments carriers, respectively. A ferromagnetic transition with highest TC ∼ 8 K has been observed for from magnetization measurements. Iso-thermal plots show that compound coercive field, 500 Oe, much smaller than in (La,Ba)(Zn,Mn)AsO. The resistivity all...
A new diluted magnetic semiconductor La(Zn1−2x Mnx Cux )SbO in bulk form has been successfully synthesized. Spins and carriers are introduced by co-doping Mn Cu into Zn sites of the parent LaZnSbO. Doping or alone does not induce ordering. Only when co-doped, can system undergo a ferromagnetic transition below Curie temperature . The shares same two-dimensional crystal structure as that 1111-type iron pnictide superconductor relatively large coercive field is observed from iso-thermal...
We report the successful synthesis of a new diluted magnetic semiconductor (Ca,Na)(Zn,Mn) 2 Sb . Na and Mn are doped into parent compound CaZn , which has same crystal structure as that “122” type iron-based superconductor CaFe As substitution for Ca Zn introduce carriers spins, respectively. Doping atoms alone up to 5% does not induce any ordering. When both co-doped, ferromagnetic ordering with maximum T C ∼ 10 K been observed. Iso-thermal magnetization shows coercive field is 245 Oe at K....
Diluted magnetic semiconductor (DMS) that combines the properties of spin and charge degrees freedom, which has potential applications in field spintronic devices. In 1990s, due to breakthrough low-temperature molecular beam epitaxy technology, scientists successfully synthesized III-V DMS (Ga, Mn)As, developed some spintronics devices accordingly. However, maximum Curie temperature Mn)As is only 200 K, still below room required for practical applications. Searching diluted semiconductors...
Abstract We perform systematic first-principles calculations on the electronic structure of n -type magnetic semiconductor Ba(Zn <?CDATA $_{1-x}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi /> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>−</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> </mml:math> Co x ) 2 As with facilitation HSE06 hybrid functional. Supercells are used to consider doping atoms, and band structures unfolded for clarity....
We investigated the magnetic properties of (La$_{1-x}$Ba$_{x}$)(Zn$_{1-x}$Mn$_{x}$)AsO with $x$ varying from 0.005 to 0.05 at an external field 1000 Oe. For doping levels $\leq$ 0.01, system remains paramagnetic down lowest measurable temperature 2 K. Only when level increases = 0.02 does ferromagnetic ordering appear. Our analysis indicates that antiferromagnetic exchange interactions dominate for as shown by negative Weiss fitted magnetization data. The becomes positive, i.e., coupling...
Abstract We report the ferromagnetism in a new bulk form Cu-based magnetic semiconductor (La,Ba)(Cu,Mn)SO, which is iso-structural to prototypical iron-based 1111-type superconductor LaFeAsO. Starting from parent compound LaCuSO, carriers are introduced via substitutions of La for Ba while spins Cu Mn. Spins mediated by carriers, develops into long range ferromagnetic ordering. The maximum Curie temperature $$T_{C}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub>...
A new diluted magnetic semiconductor (Sr, Na)(Zn, Mn)2Sb2 has been successfully synthesized by doping Na and Mn into the parent compound <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M2"> <a:msub> <a:mrow> <a:mtext>SrZn</a:mtext> </a:mrow> <a:mn>2</a:mn> </a:msub> <a:mtext>Sb</a:mtext> </a:math> , which a <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M3"> <c:msub> <c:mrow> <c:mtext>CaAl</c:mtext> </c:mrow> <c:mn>2</c:mn> </c:msub> <c:mtext>Si</c:mtext> </c:math> -type...
A pyrite system ${\mathrm{NiS}}_{2\ensuremath{-}x}{\mathrm{Se}}_{x}$ exhibits a bandwidth controlled Mott transition via (S,Se) substitutions in two-step process: the antiferromagnetic insulator (AFI) to metal (AFM) at $x\ensuremath{\sim}0.45$ followed by AFM paramagnetic (PMM) $x\ensuremath{\sim}1.0$. Among few other systems which exhibit similar transitions, $\mathrm{Ni}{(\mathrm{S},\mathrm{Se})}_{2}$ is of particular interest because large intermediate region phase diagram would provide...