Query: magnetic and electronic properties of two-

Candidate papers:

abstract: The ferromagnetism of two dimensional (2D) materials has aroused great interest in recent years, which may play an important role in the next generation magnetic devices. Herein, a series of 2D transition metal organic framework materials (TM NH MOF, TM Sc Zn) are designed, and their electronic and magnetic characters are systematically studied by means of first principles calculations. Their structural stabilities are examined through binding energies and ab initio molecular dynamics simulations. Their optimized lattice constants are correlated to the central TM atoms. These 2D TM NH MOF nanosheets exhibit various electronic and magnetic performances owing to the effective charge transfer and interaction between TM atoms and graphene linkers. Interestingly, Ni and Zn NH MOFs are nonmagnetic semiconductors (SM) with band gaps of 0.41 eV and 0.61 eV, respectively. Co and Cu NH MOFs are bipolar magnetic semiconductors (BMS) while Fe NH MOF monolayer is a half semiconductor (HSM) Furthermore, the elastic strain could tune their magnetic behaviors and transformation, which ascribes to the charge redistribution of TM 3d states. This work predicts several new 2D magnetic MOF materials, which are promising for applications in spintronics and nanoelectronics.
title: Magnetic and electronic properties of two dimensional metal organic frameworks TM3(C2NH)12
venue: Chinese Physics B
year: 2021

abstract: The peculiar magnetic properties of rare earth nitrides (RENs) make them suitable for a wide range of applications. Here, we report on a density functional theory (DFT) study of an interesting member of the family, two dimensional (2D) NdN film, using the generalized gradient approximation (GGA) including the Hubbard (U) parameter. We consider different film thicknesses, taking into account the effects of N vacancies (VN) and dopants (C and O) Formation energy values show that, even though N vacancy is the predominant defect, C and O dopants are also probable impurities in these films. Individual Nd and N magnetic moments oscillate in the presence of VN and dopants owing to the induced lattice distortions. The density of states calculations show that the 2D NdN film has a semi metallic nature, while the f orbitals are separated into fully filled and empty bands. A magnetic anisotropy energy of ~50 meV is obtained, and the easy axis aligns along the film orientation as the film thickness increases, revealing that such films are ideal candidates for spintronic applications.
author_names: S Assa Aravindh

Iman S Roqan
title: Structural, magnetic and electronic properties of two dimensional NdN: an ab initio study
year: 2019

abstract: Two dimensional CrI3 has attracted much attention as it is reported to be a ferromagnetic semiconductor with a Curie temperature of around 45 K. By performing first principles calculations, we find that the magnetic ground state of CrI3 is variable under biaxial strain. Our theoretical investigations show that the ground state of monolayer CrI3 is ferromagnetic under compression, but becomes antiferromagnetic under tension. Particularly, the transition occurs under a feasible in plane strain of around 1.8% Accompanied by the transition of the magnetic ground state, CrI3 undergoes a transition from magnetic metal to half metal to half semiconductor to spin relevant semiconductor when the strain varies from 15% to 10% We attribute these transitions to the variation of the d orbitals of Cr atoms and the p orbitals of I atoms. Generally, we report a series of magnetic and electronic phase transitions in strained CrI3, which will help both theoretical and experimental researchers in further understanding the tunable electronic and magnetic properties of CrI3 and its analogs.
author_names: Zewen Wu

Jin Yu

Shengjun Yuan
title: Strain tunable magnetic and electronic properties of monolayer CrI3.
venue: Physical chemistry chemical physics PCCP
year: 2019

abstract: We investigate the electronic and magnetic structures of two dimensional transition metal tri chalcogenide CrSiTe3 and CrGeTe3 materials by carrying out first principles calculations. The single layer CrSiTe3 and CrGeTe3 are found to be a ferromagnetic insulator, where the presence of the strong dps hybridization of Cr eg Te p plays a crucial role for the ferromagnetic coupling between Cr ions. We observe that the bandgaps and the interlayer magnetic order vary notably depending on the magnitude of on site Coulomb interaction U for Cr d electrons. The bandgaps are formed between the Cr eg conduction bands and the Te p valence bands for both CrSiTe3 and CrGeTe3 in the majority spin channel. The dominant Te p antibonding character in the valence bands just below the Fermi level is related to the decrease of the bandgap for the increase of U. We elucidate the energy band diagram, which may serve to understand the electronic and magnetic properties of the ABX3 type transition metal tri chalcogenides in general.
author_names: Sungmo Kang

Seungjin Kang

Jaejun Yu
title: Effect of Coulomb Interactions on the Electronic and Magnetic Properties of Two Dimensional CrSiTe3 and CrGeTe3 Materials
venue: Journal of Electronic Materials
year: 2018

abstract: Layered MAX phases are exfoliated into 2D single layers and multilayers, so called MXenes. Using fi rst principles calculations, the formation and electronic properties of various MXene systems, M 2 C (M Sc, Ti, V, Cr, Zr, Nb, Ta) and M 2 N (M Ti, Cr, Zr) with surfaces chemically functionalized by F, OH, and O groups, are examined. Upon appropriate surface functionalization, Sc 2 C, Ti 2 C, Zr 2 C, and Hf 2 C MXenes are expected to become semiconductors. It is also derived theoretically that functionalized Cr 2 C and Cr 2 N MXenes are magnetic. Thermoelectric calculations based on the Boltzmann theory imply that semiconducting MXenes attain very large Seebeck coeffi cients at low temperatures.
author_names: Mohammad Khazaei

Masao Arai

Taizo Sasaki

C Y Chung

Natarajan Sathiyamoorthy Venkataramanan

Mehdi Estili

Yoshio Sakka

Yoshiyuki Kawazoe
title: Novel Electronic and Magnetic Properties of Two Dimensional Transition Metal Carbides and Nitrides
year: 2013

abstract: Two dimensional (2D) nanomaterials have received increasing interest because of their unique properties for versatile applications. In this work, we present a first principles study on a new family of 2D nanostructures, Janus transition metal chalcogenide MSX (M Ti or V; and X C, N, Si, or P) monolayers, for their multifunctional applications. In this work, we show that the Janus MSXs possess diverse electronic and magnetic properties, and can be semiconducting or metallic, and nonmagnetic or magnetic, depending on their composition. We find that a TiSC monolayer with a 1H phase (TiSC 1H) is suitable as a cathode for Li ion batteries and anode materials for Na and Mg ion batteries due to its high open circuit voltage (OCV) (2.121 eV) for Li, and low OCVs upon Na (0.676 eV) and Mg (1.044 eV) intercalation, respectively. Importantly, TiSC 1H shows fast charge/discharge rates, good cycling stability, and high storage density as electrode materials for rechargeable batteries because of low ion diffusion barriers, small volume expansion and high specific capacity. We further show that TiSP 1H has the best performance in the hydrogen evolution reaction due to both its catalytic activities on the surfaces and relatively low overpotentials upon hydrogenation. Our study demonstrates that the 2D Janus MSXs may find multifunctional applications in nanodevices, spintronics, catalysis, and electrochemical energy storage.
author_names: Wenzhou Chen

Yuanju Qu

Lingmin Yao

Xianhua Hou

Xingqiang Shi

Hui Pan
title: Electronic, magnetic, catalytic, and electrochemical properties of two dimensional Janus transition metal chalcogenides
year: 2018

abstract: A two dimensional ferromagnetic semiconductor Cr2Ge2Te6 (CGT) was recently found to possess extraordinary characteristics and has great potential in the emerging field of spintronics. Using first principles calculations, we examined the stabilities of this layered system by studying the cleavage energies and phonon dispersion. The ferromagnetic ground state has an in plane spin polarization and bandgaps of about 0.26 eV by Perdew Burke Ernzerhof van der Waals and 0.91 eV by the Heyd Scuseria Ernzerhof functional. Furthermore, we employed strain engineering and an external electric field to control the electronic and magnetic properties. In addition, we studied the magnetic anisotropy energy as well as its modulation under the electric field. We predict the CGT monolayer to be the easy plane ferromagnet, and the perpendicular electric field could affect the ferromagnetic stability along different directions. Our obtained results provide guidance for the potential applications of monolayer CGT for magnetic nanodevices, spintronic, and straintronic applications.
author_names: Kangying Wang

Tao Hu

Fanhao Jia

Guodong Zhao

Yuyu Liu

Igor V Solovyev

Alexander P Pyatakov

Anatoly K Zvezdin

Wei Ren
title: Magnetic and electronic properties of Cr2Ge2Te6 monolayer by strain and electric field engineering
venue: Applied Physics Letters
year: 2019

abstract: Low dimensional materials exhibit many exceptional properties and functionalities which can be efficiently tuned by externally applied force or fields. Here we review the current status of research on tuning the electronic and magnetic properties of low dimensional carbon, boron nitride, metal dichalcogenides, phosphorene nanomaterials by applied engineering strain, external electric field and interaction with substrates, etc, with particular focus on the progress of computational methods and studies. We highlight the similarities and differences of the property modulation among one and two dimensional nanomaterials. Recent breakthroughs in experimental demonstration of the tunable functionalities in typical nanostructures are also presented. Finally, prospective and challenges for applying the tunable properties into functional devices are discussed. WIREs Comput Mol Sci 2016, 6:324 350. doi: 10.1002/wcms.1251
author_names: Zhuhua Zhang

Xiaofei Liu

Jin Zhong Yu

Yang Hang

Y Li

Yufeng Guo

Ying Xu

Xu Sun

Jianxin Zhou

Wanlin Guo
title: Tunable electronic and magnetic properties of two dimensional materials and their one dimensional derivatives
venue: Wiley interdisciplinary reviews. Computational molecular science
year: 2016

abstract: Two dimensional (2D) nanomaterials have attracted extensive interest due to their unique properties and versatile applications. In the current work, a new family of 2D nanostructures, 2D transition metal phosphide monolayer (M2P) is designed to find its multifunctional applications on the basis of density functional theory (DFT) calculations. We show that the 2D M2P monolayers are thermodynamically stable by carrying out molecular dynamic simulations, analyzing their phonon dispersions, and calculating their mechanical properties. We find that all of the stable 2D M2P monolayers are metallic, and their magnetic states strongly depend on the transition metals and geometric phases. We further demonstrate that 2D W2P and Fe2P monolayers in the 2H phase show the best catalytic performance in hydrogen evolution reaction (HER) due to the relatively low overpotentials at high hydrogen coverage. Importantly, oxygen functionalization can efficiently improve the HER activities of the 2D M2P monolayers at low hydro.
author_names: Yangfan Shao

Xingqiang Shi

Hui Pan
title: Electronic, Magnetic, and Catalytic Properties of Thermodynamically Stable Two Dimensional Transition Metal Phosphides
year: 2017

abstract: Abstract We report a detailed density functional theory investigation for ACr2As2 (A Sr, Ba) which are isostructural to their iron counterparts AFe2As2, parent compounds of iron based superconductors. The calculated results for these two compounds are quite similar, indicating that the A site ions have only a relatively small impact on the magnetic and electronic structures. It is found that both ACr2As2 favor an itinerant antiferromagnetic ground state with G type spin arrangement, and possess a sizable magnetocrystalline anisotropy energy with the easy axis directed along the c axis perpendicular to the CrAs plane. Furthermore, the optimized lattice constants and internal atomic parameter of ACr2As2 are found to be sensitive to magnetic ordering, which implies the presence of a magnetostructural coupling effect.
author_names: Wenqi Zhou

P Hu

Shu-wei Li

Shuxiang Wu
title: First principles study of the magnetic and electronic properties of ACr2As2 (A Sr, Ba)
venue: Journal of Magnetism and Magnetic Materials
year: 2019