相关论文: Halogen Doped Electronic Properties of 2D ZnO: A F…
A novel and direct method is proposed to assess the doping limits of semiconducting materials. Applied to the case of ZnO, our first-principles calculations demonstrate that p-type ZnO is thermodynamically unstable.
Bandgap control is of central importance for semiconductor technologies. The traditional means of control is to dope the lattice chemically, electrically or optically with charge carriers. Here, we demonstrate for the first time a widely…
High-transition-temperature (high-Tc) superconductivity develops near antiferromagnetic phases, and it is possible that magnetic excitations contribute to the superconducting pairing mechanism. To assess the role of antiferromagnetism, it…
Monitoring electronic properties of 2D materials is an essential step to open a way for applications such as electronic devices and sensors. From this perspective, Bernal bilayer graphene (BLG) is a fairly simple system that offers great…
Doping lithium-ion battery electrode materials LiMO$_2$ (M = Co, Ni, Mn) with impurities has been shown to be an effective way to optimize their electrochemical properties. Here, we report a detailed first-principles study of layered oxides…
Magnetic 3d-ions doped into wide-gap oxides show signatures of room temperature ferromagnetism, although their concentration is two orders of magnitude smaller than that in conventional magnets. The prototype of these exceptional materials…
We present a systematic ab initio study based on density-functional calculations to understand impurity effects in iron-based superconductors. Effective tight-binding Hamiltonians for the d-bands of LaFeAsO with various transition-metal…
We present an extended study of single impurity atoms and atomic swaps in half-metallic CrAs, CrSb and CrSe zinc-blende compounds. Although the perfect alloys present a rather large gap in the minority-spin band, all defects under study,…
Based on a minimal two-orbital model [Tai {\it et al.}, Europhys. Lett. \textbf{103}, 67001 (2013)], which captures the canonical electron-hole-doping phase diagram of the iron-pnictide BaFe$_{2}$As$_{2}$, we study the evolution of…
The samples of Ga doped Cr2O3 oxide have been prepared using chemical co-precipitation route. X-ray diffraction pattern and Raman spectra have confirmed rhombohedral crystal structure with space group R3-C. Magnetic measurement has…
A first-principles study has been performed to evaluate the electronic and optical properties of wurtzite Zn1-xCdxO up to x=0.25. We have employed the Perdew-Burke-Ernzerhof (PBE) form of generalized gradient approximation within the…
Several experimental studies have referred to the grain boundary (GB) defect as the origin of the ferromagnetism in ZnO. However, the mechanism of this hypothesis has never been confirmed. Present study investigates the atomic structure and…
Heusler alloys with Mn and Co have been found to exhibit interesting electronic and magnetic properties. Mn$_2$CoAl is well known SGS compound while Mn$_2$CoGa has weak half metallic character. By using plane wave pseudo-potential method,…
The recent progress in formation of two-dimensional (2D) GaN by a migration-enhanced encapsulated technique opens up new possibilities for group III-V 2D semiconductors with a band gap within the visible energy spectrum. Using…
We present a 31P NMR study of the coupled spin 1/2 ladder compound BiCu2PO6. In the pure material, intrinsic susceptibility and dynamics show a spin gap of about . Substitution of non magnetic Zn or magnetic Ni impurity at Cu site induces a…
We report magnetism in carbon doped ZnO. Our first-principles calculations based on density functional theory predicted that carbon substitution for oxygen in ZnO results in a magnetic moment of 1.78 $\mu_B$ per carbon. The theoretical…
Impurity effect is systematically studied in doped Haldane material Pb(Ni$_{1-x}$$M_x$)$_2$V$_2$O$_8$ ($M$ = Mn, Co, Cu, and Mg) by use of DC and AC susceptibility, and heat capacity measurements. The occurrence of three-dimensional ordered…
PbPdO$_2$, a ternary compound containing the lone-pair active ion Pb$^{2+}$ and the square-planar d$^8$ Pd$^{2+}$ ion, has attracted recent interest because of the suggestion that its electronic structure, calculated within density…
The influence of non-magnetic impurities on the spectrum and dynamical spin structure factor of a model for CuGeO$_3$ is studied. A simple extension to Zn-doped ${\rm Sr Cu_2 O_3}$ is also discussed. Using Exact Diagonalization techniques…
In this work we have employed density-functional theory with hybrid functionals to investigate the atomic and electronic structure of bare and hydrogenated Mn doped ZnO nanowires with small diameter. We determine changes in magnetic and…