scholarly journals Nearly room temperature ferromagnetism in a magnetic metal-rich van der Waals metal

2020 ◽  
Vol 6 (3) ◽  
pp. eaay8912 ◽  
Author(s):  
Junho Seo ◽  
Duck Young Kim ◽  
Eun Su An ◽  
Kyoo Kim ◽  
Gi-Yeop Kim ◽  
...  
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Van Der Waals ◽  
Spin Current ◽  
Perpendicular Magnetic Anisotropy ◽  
Long Distance ◽  
Effective Spin ◽  
Experimental Realization ◽  
Spintronic Devices ◽  
Source Operation

In spintronics, two-dimensional van der Waals crystals constitute a most promising material class for long-distance spin transport or effective spin manipulation at room temperature. To realize all-vdW-material–based spintronic devices, however, vdW materials with itinerant ferromagnetism at room temperature are needed for spin current generation and thereby serve as an effective spin source. We report theoretical design and experimental realization of a iron-based vdW material, Fe4GeTe2, showing a nearly room temperature ferromagnetic order, together with a large magnetization and high conductivity. These properties are well retained even in cleaved crystals down to seven layers, with notable improvement in perpendicular magnetic anisotropy. Our findings highlight Fe4GeTe2 and its nanometer-thick crystals as a promising candidate for spin source operation at nearly room temperature and hold promise to further increase Tc in vdW ferromagnets by theory-guided material discovery.

Room-Temperature Ferromagnetism in (Zn,Mn,Sn)As2Thin Films Applicable to InP-Based Spintronic Devices

2011 ◽  
Vol 50 (5) ◽  
pp. 05FB02 ◽  
Author(s):  
Naotaka Uchitomi ◽  
Hiroto Oomae ◽  
Joel T. Asubar ◽  
Hironori Endo ◽  
Yoshio Jinbo
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Spintronic Devices

scholarly journals Strong intrinsic room-temperature ferromagnetism in freestanding non-van der Waals ultrathin 2D crystals

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hao Wu ◽  
Wenfeng Zhang ◽  
Li Yang ◽  
Jun Wang ◽  
Jie Li ◽  
...  
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Van Der Waals ◽  
Ambient Air ◽  
Critical Importance ◽  
Functional Possibility ◽  
Topological Quantum ◽  
Unit Cells ◽  
Optical And Mechanical Properties ◽  
2D Crystals

AbstractControl of ferromagnetism is of critical importance for a variety of proposed spintronic and topological quantum technologies. Inducing long-range ferromagnetic order in ultrathin 2D crystals will provide more functional possibility to combine their unique electronic, optical and mechanical properties to develop new multifunctional coupled applications. Recently discovered intrinsic 2D ferromagnetic crystals such as Cr2Ge2Te6, CrI3 and Fe3GeTe2 are intrinsically ferromagnetic only below room temperature, mostly far below room temperature (Curie temperature, ~20–207 K). Here we develop a scalable method to prepare freestanding non-van der Waals ultrathin 2D crystals down to mono- and few unit cells (UC) and report unexpected strong, intrinsic, ambient-air-robust, room-temperature ferromagnetism with TC up to ~367 K in freestanding non-van der Waals 2D CrTe crystals. Freestanding 2D CrTe crystals show comparable or better ferromagnetic properties to widely-used Fe, Co, Ni and BaFe12O19, promising as new platforms for room-temperature intrinsically-ferromagnetic 2D crystals and integrated 2D devices.

scholarly journals Evidence for spin current driven Bose-Einstein condensation of magnons

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
B. Divinskiy ◽  
H. Merbouche ◽  
V. E. Demidov ◽  
K. O. Nikolaev ◽  
L. Soumah ◽  
...  
Keyword(s):  
Room Temperature ◽  
Chemical Potential ◽  
Spin Current ◽  
Einstein Condensation ◽  
Electronic Control ◽  
Spintronic Devices ◽  
Bose Einstein Condensation ◽  
Magnetic Insulators ◽  
Spatially Extended ◽  
Bose Einstein

AbstractThe quanta of magnetic excitations – magnons – are known for their unique ability to undergo Bose-Einstein condensation at room temperature. This fascinating phenomenon reveals itself as a spontaneous formation of a coherent state under the influence of incoherent stimuli. Spin currents have been predicted to offer electronic control of Bose-Einstein condensates, but this phenomenon has not been experimentally evidenced up to now. Here we show that current-driven Bose-Einstein condensation can be achieved in nanometer-thick films of magnetic insulators with tailored nonlinearities and minimized magnon interactions. We demonstrate that, above a certain threshold, magnons injected by the spin current overpopulate the lowest-energy level forming a highly coherent spatially extended state. We quantify the chemical potential of the driven magnon gas and show that, at the critical current, it reaches the energy of the lowest magnon level. Our results pave the way for implementation of integrated microscopic quantum magnonic and spintronic devices.

Strong room-temperature ferromagnetism in VSe2 monolayers on van der Waals substrates

2018 ◽  
Vol 13 (4) ◽  
pp. 289-293 ◽  
Author(s):  
Manuel Bonilla ◽  
Sadhu Kolekar ◽  
Yujing Ma ◽  
Horacio Coy Diaz ◽  
Vijaysankar Kalappattil ◽  
...  
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Van Der Waals

scholarly journals Room temperature ferromagnetism in ultra-thin van der Waals crystals of 1T-CrTe2

Nano Research ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3358-3363 ◽  
Author(s):  
Xingdan Sun ◽  
Wanying Li ◽  
Xiao Wang ◽  
Qi Sui ◽  
Tongyao Zhang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Van Der Waals

scholarly journals Nearly Room-Temperature Ferromagnetism in a Pressure-Induced Correlated Metallic State of the van der Waals Insulator CrGeTe3

2021 ◽  
Vol 127 (21) ◽  
Author(s):  
Dilip Bhoi ◽  
Jun Gouchi ◽  
Naoka Hiraoka ◽  
Yufeng Zhang ◽  
Norio Ogita ◽  
...  
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Van Der Waals ◽  
Metallic State

THE GROWTH AND CHARACTERIZATION OF ROOM TEMPERATURE FERROMAGNETIC WIDEBAND-GAP MATERIALS FOR SPINTRONIC APPLICATIONS

2006 ◽  
Vol 16 (02) ◽  
pp. 515-543
Author(s):  
MATTHEW H. KANE ◽  
MARTIN STRASSBURG ◽  
WILLIAM E. FENWICK ◽  
ALI ASGHAR ◽  
IAN T. FERGUSON
Keyword(s):  
Room Temperature ◽  
Magnetic Semiconductors ◽  
Room Temperature Ferromagnetism ◽  
Dilute Magnetic Semiconductors ◽  
Chemical Vapor ◽  
Wide Bandgap ◽  
Organic Chemical ◽  
Ferromagnetic Behavior ◽  
Spintronic Devices

Wide-bandgap dilute magnetic semiconductors (DMS), such as transition-metal doped ZnO and GaN , have gained attention for use in spintronic devices because of predictions and experimental reports of room temperature ferromagnetism which may enable their use in spintronic devices. However, there has been some debate over the source of ferromagnetism in these materials. This paper focuses on the high quality growth of wide bandgap DMS, and the characterization of Zn 1-x Mn x O produced by melt-growth techniques and Ga 1-x Mn x N grown by metal organic chemical vapor deposition (MOCVD). High resolution X-ray diffraction results revealed no second phases in either the ZnO crystals or the GaN films. Undoped as-grown, bulk crystals of Zn 1-x Mn x O and Zn 1-x Co x O crystals are shown to be paramagnetic at all temperatures. In contrast, the Ga 1-x Mn x N films showed ferromagnetic behavior at room temperature under optimum growth conditions. Experimental identification of the Mn ion charge state and the presence of bands in the bandgap of GaN are investigated by optical spectroscopy and electron spin paramagnetic resonance (EPR). It is shown that the broadening of states in the Mn 3d shell scaled with Mn concentration, and that optical transitions due to this band correlated with the strong ferromagnetism in these samples. However, this band disappeared with an increase in free electron concentration provided by either annealing or doping. Raman studies of Ga 1-x Mn x N revealed two predominant Mn -related modes featured with increasing concentration, a broad disorder related structure at 300cm-1 and a sharper peak at 669cm-1 This works show that the development of practical ferromagnetic wide bandgap DMS materials for spintronic applications will require both the lattice site introduction of Mn as well as careful control of the background defect concentration to optimize these materials.

scholarly journals Room-temperature intrinsic ferromagnetism in epitaxial CrTe2 ultrathin films

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaoqian Zhang ◽  
Qiangsheng Lu ◽  
Wenqing Liu ◽  
Wei Niu ◽  
Jiabao Sun ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Large Scale ◽  
Room Temperature ◽  
Magnetic Circular Dichroism ◽  
Room Temperature Ferromagnetism ◽  
Perpendicular Magnetic Anisotropy ◽  
Interlayer Coupling ◽  
Angle Resolved Photoemission Spectroscopy ◽  
Device Applications ◽  
Intrinsic Ferromagnetism

AbstractWhile the discovery of two-dimensional (2D) magnets opens the door for fundamental physics and next-generation spintronics, it is technically challenging to achieve the room-temperature ferromagnetic (FM) order in a way compatible with potential device applications. Here, we report the growth and properties of single- and few-layer CrTe2, a van der Waals (vdW) material, on bilayer graphene by molecular beam epitaxy (MBE). Intrinsic ferromagnetism with a Curie temperature (TC) up to 300 K, an atomic magnetic moment of ~0.21 $${\mu }_{{\rm{B}}}$$ μ B /Cr and perpendicular magnetic anisotropy (PMA) constant (Ku) of 4.89 × 105 erg/cm3 at room temperature in these few-monolayer films have been unambiguously evidenced by superconducting quantum interference device and X-ray magnetic circular dichroism. This intrinsic ferromagnetism has also been identified by the splitting of majority and minority band dispersions with ~0.2 eV at Г point using angle-resolved photoemission spectroscopy. The FM order is preserved with the film thickness down to a monolayer (TC ~ 200 K), benefiting from the strong PMA and weak interlayer coupling. The successful MBE growth of 2D FM CrTe2 films with room-temperature ferromagnetism opens a new avenue for developing large-scale 2D magnet-based spintronics devices.

scholarly journals Highly‐Tunable Intrinsic Room‐Temperature Ferromagnetism in 2D van der Waals Semiconductor Cr x Ga 1− x Te

2021 ◽  
pp. 2103173
Author(s):  
Gaojie Zhang ◽  
Hao Wu ◽  
Liang Zhang ◽  
Shanfei Zhang ◽  
Li Yang ◽  
...  
Keyword(s):  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Van Der Waals

Two-Dimensional [CaCl]+●e- and its strippable feasibility as an applicable electride with room temperature ferromagnetism and extremely low work function

2021 ◽  
Author(s):  
Weizhen Meng ◽  
Xiaoming Zhang ◽  
Ying Liu ◽  
Xuefang Dai ◽  
HongLi Gao ◽  
...  
Keyword(s):  
Work Function ◽  
Room Temperature ◽  
Room Temperature Ferromagnetism ◽  
Two Dimensional ◽  
Spintronic Devices ◽  
Work Functions ◽  
Application Prospects

Electrides in two-dimensional (2D) scale, especially those capture inherent magnetism and low work functions, have shown great application prospects in nanoscale spintronic devices and electronic emitters. However, searching ideal 2D...

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