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相关论文: Controlling the magnetism of oxygen surface vacanc…

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A magnetite (Fe3O4) single crystal (111) surface has been studied at various oxygen-iron surface stoichiometries. The stoichiometry was modified by controlling the in-situ sample anneal conditions. We have found the conditions that lead to…

软凝聚态物质 · 物理学 2007-05-23 N. Berdunov , S. Murphy , G. Mariotto , I. V. Shvets

The occurence of spin-polarization at ZrO$_{2}$, Al$_{2}$O$_{3}$ and MgO surfaces is proved by means of \textit{ab-initio} calculations within the density functional theory. Large spin moments, as high as 1.56 $\mu_B$, develop at O-ended…

材料科学 · 物理学 2009-11-11 S. Gallego , J. I. Beltran , J. Cerda , M. C. Munoz

Strontium titanate is an incipient ferroelectric in which superconductivity emerges at exceptionally low doping levels. Remarkably, stabilizing the polar phase through strain or chemical substitution has been shown to significantly enhance…

材料科学 · 物理学 2022-12-15 Alex Hallett , John W. Harter

We present theoretical evidence for local magnetic moments on Ti3+ ions in oxygen-deficient anatase and rutile TiO2 observed in a recent experiment [S. Zhou, et al., Phys. Rev. B 79, 113201 (2009)]. Results of our first-principles GGA+U…

材料科学 · 物理学 2010-01-20 Kesong Yang , Ying Dai , Baibiao Huang , Yuanping Feng

We perform a theoretical study of the magnetism induced in transition metal dioxides ZrO2 and TiO2 by substitution of the cation by a vacancy or an impurity from the groups 1A or 2A of the periodic table, where the impurity is either K or…

材料科学 · 物理学 2013-06-27 Frantisek Maca , Josef Kudrnovsky , Vaclav Drchal , Georges Bouzerar

The atomic thickness of two-dimensional (2D) materials provides a unique opportunity to control material properties and engineer new functionalities by electrostatic doping. Electrostatic doping has been demonstrated to tune the electrical…

材料科学 · 物理学 2018-08-01 Shengwei Jiang , Lizhong Li , Zefang Wang , Kin Fai Mak , Jie Shan

{\it Ab initio} calculations within density functional theory with generalized gradient approximation have been performed to study the effects of oxygen vacancies on the electronic structure and magnetism in undoped V$_2$O$_{5-x}$ ($0 < x <…

材料科学 · 物理学 2008-02-12 Zhi Ren Xiao , Guang Yu Guo , Po Han Lee , Hua Shu Hsu , Jung Chun Andrew Huang

Understanding the diffusion of oxygen vacancies in oxides under different external stimuli is crucial for the design of ion-based electronic devices, improve catalytic performance, etc. In this manuscript, using an external electric field…

材料科学 · 物理学 2018-07-04 Lucía Iglesias , Andrés Gómez , Martí Gich , Francisco Rivadulla

Strontium titanate, SrTiO3, a widely used substrate material for electronic oxide thin film devices, has provided many interesting features. In a combination with a similar oxide material, LaAlO3, it has recently received great interest. It…

This letter reports on the magnetic properties of Ti1-xCoxO2 anatase phase nanopowders with different Co contents. It is shown that oxygen vacancies play a fundamental role in promoting the long-range ferromagnetic order in the material…

材料科学 · 物理学 2009-05-01 L. C. J. Pereira , M. R. Nunes , O. C. Monteiro , A. J. Silvestre

We investigate the effect of low-coordinated surface atoms on the defect-induced magnetism in MgO nanocrystallites using hybrid density functional theory calculations. It has been demonstrated that when Mg vacancies are introduced at the…

介观与纳米尺度物理 · 物理学 2015-06-11 Takashi Uchino , Toshinobu Yoko

Magnetisms in $p$-type monolayer GaX (X=S,Se) is investigated by performing density-functional calculations. Due to the large density of states near the valence band edge, these monolayer semiconductors are ferromagnetic within a small…

介观与纳米尺度物理 · 物理学 2014-09-18 Sianxin Wu , Xia Dai , Hongyi Yu , Heng Fan , Jiangping Hu , Wang Yao

In this paper we show that ferromagnetism can be induced in pure TiO2 single crystals by oxygen ion irradiation. By combining x-ray diffraction, Raman-scattering, and electron spin resonance spectroscopy, a defect complex, \emph{i.e.}…

Switchability of materials properties by applying controlled stimuli such as voltage pulses is an emerging field of study with applicability in adaptive and programmable devices like neuromorphic transistors or non-emissive smart displays.…

While defects such as oxygen vacancies in correlated materials can modify their electronic properties dramatically, understanding the microscopic origin of electronic correlations in materials with defects has been elusive. Lanthanum…

强关联电子 · 物理学 2021-02-24 Xingyu Liao , Vijay Singh , Hyowon Park

The magnetism of C-doped SnO$_{2}$ (001) surfaces is studied using first-principles calculations. It is found that carbon does not induce magnetism in bulk SnO$_{2}$ when located at the oxygen site, but shows a large magnetic moment at the…

材料科学 · 物理学 2010-02-13 Gul Rahman , Víctor M. García-Suárez

We employ spin-polarized (SP) STM to study the spin-dependent tunneling between a magnetite (111) sample and an antiferromagnetic tip through a vacuum barrier at room temperature. Atomic scale STM images show significant magnetic contrast…

材料科学 · 物理学 2007-05-23 N. Berdunov , S. Murphy , G. Mariotto , I. V. Shvets

First principles calculations of the O surfaces of Co-ZnO show that substitutional Co ions develop large magnetic moments which long-range coupling depends on their mutual distance. The local spin polarization induced at the O atoms is…

材料科学 · 物理学 2009-11-13 N. Sanchez , S. Gallego , M. C. Munoz

Oxygen vacancies in the perovskite insulator SrTiO$_3$ free electrons that couple with other physical degrees of freedom such as lattice, orbital, and spin. This leads to the emergence of exotic quantum states such as superconductivity and…

强关联电子 · 物理学 2023-06-13 Liang Si , Xiaochao Wang , Paul Worm , Wei Peng , Minjae Kim , Lingfei Wang , Karsten Held

We report on the magnetic, resistive, and structural studies of perovskite La$_{1/3}$Sr$_{2/3}$CoO$_{3-\delta}$. By using the relation of synthesis temperature and oxygen partial pressure to oxygen stoichiometry obtained from…

材料科学 · 物理学 2009-11-11 S. Kolesnik , B. Dabrowski , J. Mais , M. Majjiga , O Chmaissem , A. Baszczuk , J. D. Jorgensen