scholarly journals Dynamic transition of current-driven single-skyrmion motion in a room-temperature chiral-lattice magnet

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Licong Peng ◽  
Kosuke Karube ◽  
Yasujiro Taguchi ◽  
Naoto Nagaosa ◽  
Yoshinori Tokura ◽  
...  
Keyword(s):  
Electric Current ◽  
Motion Tracking ◽  
Room Temperature ◽  
Dynamic Transition ◽  
Spintronic Devices ◽  
Transmission Electron ◽  
Flow Motion ◽  
Lorentz Transmission Electron Microscopy ◽  
And Control

AbstractDriving and controlling single-skyrmion motion promises skyrmion-based spintronic applications. Recently progress has been made in moving skyrmionic bubbles in thin-film heterostructures and low-temperature chiral skyrmions in the FeGe helimagnet by electric current. Here, we report the motion tracking and control of a single skyrmion at room temperature in the chiral-lattice magnet Co9Zn9Mn2 using nanosecond current pulses. We have directly observed that the skyrmion Hall motion reverses its direction upon the reversal of skyrmion topological number using Lorentz transmission electron microscopy. Systematic measurements of the single-skyrmion trace as a function of electric current reveal a dynamic transition from the static pinned state to the linear flow motion via a creep event, in agreement with the theoretical prediction. We have clarified the role of skyrmion pinning and evaluated the intrinsic skyrmion Hall angle and the skyrmion velocity in the course of the dynamic transition. Our results pave a way to skyrmion applications in spintronic devices.

Strengthening Evaluation in a Composite Mg-RE Alloy Using TEM

2011 ◽  
Vol 678 ◽  
pp. 75-84 ◽  
Author(s):  
Marcello Cabibbo
Keyword(s):  
Electron Microscopy ◽  
Metal Matrix ◽  
Room Temperature ◽  
Strengthening Mechanism ◽  
Composite Alloy ◽  
Specific Strength ◽  
High Specific Strength ◽  
Transmission Electron ◽  
Sic Ceramic

Magnesium alloys containing rare earth elements are known to have high specific strength and corrosion resistance. The addition of SiC ceramic particles makes the metal matrix composite stronger with better wear and creep resistance and a still good machinability. The role of the reinforcement particles to the enhanced strength can be quantitatively evaluated using transmission electron microscopy (TEM). This paper presents a quantitative strengthening evaluation in a SiC Mg-RE composite alloy. The different contributions were determined by TEM inspections. The microstructure strengthening mechanism was studied after room temperature compression specimens. The way of combining the different contributions and the comparison to the measured yield stress, is also discussed and justified.

Room temperature p-orbital magnetism in carbon chains and the role of group IV, V, VI, and VII dopants

Nanoscale ◽  
2018 ◽  
Vol 10 (23) ◽  
pp. 11186-11195 ◽  
Author(s):  
C. H. Wong ◽  
E. A. Buntov ◽  
A. F. Zatsepin ◽  
J. Lyu ◽  
R. Lortz ◽  
...  
Keyword(s):  
Rare Earth ◽  
Transition Metals ◽  
Room Temperature ◽  
Group Iv ◽  
Rare Earth Ions ◽  
Next Generation ◽  
Spintronic Devices ◽  
Carbon Chains ◽  
Orbital Magnetism

The study of magnetism without the involvement of transition metals or rare earth ions is considered the key to the fabrication of next-generation spintronic devices.

Transformation Crystallography and Plasticity of the δ→α′ Transformation in Plutonium Alloys

2003 ◽  
Vol 802 ◽  
Author(s):  
C. R. Krenn ◽  
M. A. Wall ◽  
A. J. Schwartz
Keyword(s):  
Habit Plane ◽  
Room Temperature ◽  
Face Centered Cubic ◽  
Thermally Activated ◽  
Delta Phase ◽  
Transmission Electron ◽  
Δ Phase ◽  
Face Centered ◽  
Prime Phase

ABSTRACTIn delta phase Pu-Ga alloys, the transformation from the ductile face-centered cubic (fcc) δ phase that is retained at room temperature to the brittle low-temperature monoclinic alpha-prime phase is a thermally activated diffusionless transformation with double-c kinetics. Accurate modeling of the phase transformation requires detailed understanding of the role of plastic flow during the transformation and of the crystallographic transformation path. Using transmission electron microscopy (TEM), we find a significant increase in dislocation density in δ near the α′ plates, which suggests that plastic deformation contributes to the accommodation of the 20% reduction in volume during the transformation. Analysis of a series of optical micrographs of partially transformed alloys suggests that the α′ habit plane is usually nearly perpendicular to <111> δ. However, a small number of TEM observations support a habit plane near <112> or <123>, in agreement with earlier work.

On the Role of Characterization in the Design of Interfaces in Nanoscale Materials Technology

2004 ◽  
Vol 10 (3) ◽  
pp. 324-335 ◽  
Author(s):  
S.P. Ringer ◽  
K.R. Ratinac
Keyword(s):  
Three Dimensional ◽  
Atom Probe ◽  
Turbine Rotor ◽  
Clay Nanocomposites ◽  
Multimodal Approach ◽  
Transmission Electron ◽  
Different Types ◽  
And Control

This work reviews recent research on the design and control of interfaces in engineering nanomaterials. Four case studies are presented that demonstrate the power of a multimodal approach to the characterization of different types of interfaces. We have used a combination of conventional, high resolution, and analytical transmission electron microscopy, microbeam electron diffraction, and three-dimensional atom probe to study polymer–clay nanocomposites, turbine rotor steels used for power generation, multicomponent aluminum alloys, and nanocrystalline magnetic materials.

Preparation and phase control of nanocrystalline silver indium sulfides via a hydrothermal route

2001 ◽  
Vol 16 (12) ◽  
pp. 3411-3415 ◽  
Author(s):  
J. Q. Hu ◽  
B. Deng ◽  
K. B. Tang ◽  
C. R. Wang ◽  
Y. T. Qian
Keyword(s):  
Room Temperature ◽  
Photoelectron Spectra ◽  
Hydrothermal Route ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns ◽  
And Control ◽  
Microscopy Images ◽  
Room Temperature Raman Spectrum ◽  
Weak Peak

A hydrothermal route was proposed to prepare and control nanocrystalline silver indium sulfides (orthorhombic AgInS2, tetragonal AgInS2, and cubic AgIn5S8). The reaction was carried out in an autoclave in the temperature range of 100–280 °C with AgCl, InCl3, and thiourea as reactants. X-ray powder diffraction patterns and transmission electron microscopy images showed that the products were AgInS2 and AgIn5S8 phases and well crystallized with grain diameter in the range of 20–70 nm. X-ray photoelectron spectra of the single AgIn5S8 phase revealed the surface stoichiometry (AgIn5.05S8.11), and its room temperature Raman spectrum showed a strong peak at 130 cm−1 and a weak peak at around 290 cm−1. The influence of reaction temperature on the phases in the final products was investigated. A possible reaction mechanism of the formation of silver indium sulfides was also briefly discussed.

scholarly journals PERANCANGAN PIRANTI LUNAK RESPONSIVE UNTUK MONITORING RUANGAN SERVER MENGUNAKAN NODEMCU ESP8266 BERBASIS INTERNET OF THINGS

2020 ◽  
Vol 22 (3) ◽  
pp. 270-277
Author(s):  
M. Safii ◽  
Novi Indrayani
Keyword(s):  
Room Temperature ◽  
Large Data ◽  
Air Conditioner ◽  
Web Based ◽  
Data Usage ◽  
And Control ◽  
Continuous Use ◽  
The Impact

The role of the server is very important as a data service provider and control for an office that has a very large data usage and control system. This can also affect the temperature in the server room which has computer devices and other control systems because of its continuous use. The impact of temperature that is outside of its tolerance value due to the dead air conditioner without being noticed by the officer or server operator can result in damage to the hardware devices in the server room. Monitoring and measuring server room temperature is not possible to be done directly and accurately in all conditions due to several inhibiting factors in obtaining temperature information. With these problems, a temperature monitoring prototype was built using node MCU ESP 2866 and DHT 21 sensor with responsive web-based software so that it can be easily seen on various PC and smartphone monitors. This software can be used in server rooms to provide room temperature information to operators or server officers. The long-term objective of this research is expected to provide information Real-time temperature conditions in a responsive web-based server room.

Ultra-Hard Nanostructured Al-Si Thin Films

2005 ◽  
Vol 494 ◽  
pp. 13-18
Author(s):  
Velimir Radmilović ◽  
D. Mitlin ◽  
U. Dahmen
Keyword(s):  
Room Temperature ◽  
Single Phase ◽  
Mechanical Performance ◽  
High Rate ◽  
Hard Phase ◽  
Two Phase ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
Dense Distribution

We show that it is possible to use high rate co-evaporation of Al and Si onto room temperature substrates to achieve a novel two-phase nanoscale microstructure. These nanocomposites have a hardness as high as 4GPa (Al-23at.%Si), and display noticeable plasticity. Films with compositions of Al-12at.%Si and pure Al (used as baseline) were analyzed using transmission electron microscopy (TEM). The scale of the Al-12at.%Si microstructure is an order of magnitude finer compared to that of pure Al films. It consists of a dense distribution of spherical nanoscale Si particles separating irregularly-shaped small Al grains. These new structures may have a mechanical performance advantage over conventional single phase nanomaterials due to the role of the dispersed hard phase in promoting strain hardening.

scholarly journals Evolution and competition between chiral spin textures in nanostripes with D2d symmetry

2020 ◽  
Vol 6 (49) ◽  
pp. eabc0723
Author(s):  
Jagannath Jena ◽  
Börge Göbel ◽  
Vivek Kumar ◽  
Ingrid Mertig ◽  
Claudia Felser ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Applied Magnetic Field ◽  
Room Temperature ◽  
Memory Storage ◽  
Heusler Compound ◽  
Storage Devices ◽  
Transmission Electron ◽  
Lorentz Transmission Electron Microscopy

Chiral spin textures are of considerable interest for applications in spintronics. It has recently been shown that magnetic materials with D2d symmetry can sustain several distinct spin textures. Here, we show, using Lorentz transmission electron microscopy, that single and double chains of antiskyrmions can be generated at room temperature in nanostripes less than 0.5 μm in width formed from the D2d Heusler compound Mn1.4Pt0.9Pd0.1Sn. Typically, truncated helical spin textures are formed in low magnetic fields, whose edges are terminated by half antiskyrmions. These evolve into chains of antiskyrmions with increasing magnetic field. Single chains of these objects are located in the middle of the nanostripes even when the stripes are much wider than the antiskyrmions. Moreover, the chains can even include elliptical Bloch skyrmions depending on details of the applied magnetic field history. These findings make D2d materials special and highly interesting for applications such as magnetic racetrack memory storage devices.

scholarly journals Role of Synadenium grantii latex proteases in nematicidal activity on Meloidogyne incognita and Panagrellus redivivus

2019 ◽  
Vol 79 (4) ◽  
pp. 665-668 ◽  
Author(s):  
E. H. Gomes ◽  
F. E. F. Soares ◽  
D. C. Souza ◽  
L. T. Lima ◽  
B. L. Sufiate ◽  
...  
Keyword(s):  
Meloidogyne Incognita ◽  
Room Temperature ◽  
Chitinase Activity ◽  
Nematicidal Activity ◽  
Control Groups ◽  
Panagrellus Redivivus ◽  
Significant Difference ◽  
And Control ◽  
Plant Latex

Abstract Synadenium grantii is a Euphorbiaceae plant commonly found in Brazil, known as Janaúba or Leitosinha, whose latex is traditionally used for several purposes. However, it is not known whether the nematicidal action of this plant latex occurs due to the action of proteases. The present work aims to evaluate the nematicidal activity of proteases from Synadenium grantii latex on Meloidogyne incognita and Panagrellus redivivus. S. grantii latex used in the present study was collected from specimens found in Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brazil. The drained latex was collected in Eppendorf microtubes and immediately stored on ice at 4 °C. After this extraction, the latex was frozen (-20 °C) during 2 hours, thawed at room temperature (25 °C) and centrifuged at 10,000 g at 4 °C for 30 minutes to remove larger particles and concentrate the proteases. After the centrifugation, assays of enzymatic activity were performed in order to know in which of the phases the enzymes were found. S. grantii latex presented protease, but no chitinase activity. The results show that there was a significant difference (p <0.01) between the treated and control groups, with 100% mortality of Meloidogyne incognita and 72% average mortality of Panagrellus redivivus. In addition, it was demonstrated that the nematicidal action occurred due to the action of the proteases, since the control was only differentiated from the treatment by the presence of the enzymes with biological activity.

scholarly journals Dipolar-stabilized first and second-order antiskyrmions in ferrimagnetic multilayers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael Heigl ◽  
Sabri Koraltan ◽  
Marek Vaňatka ◽  
Robert Kraft ◽  
Claas Abert ◽  
...  
Keyword(s):  
Dipole Interaction ◽  
Dipolar Interaction ◽  
Second Order ◽  
Microscopy Imaging ◽  
Micromagnetic Simulations ◽  
Spintronic Devices ◽  
Transmission Electron ◽  
Wide Range ◽  
Lorentz Transmission Electron Microscopy

AbstractSkyrmions and antiskyrmions are topologically protected spin structures with opposite vorticities. Particularly in coexisting phases, these two types of magnetic quasi-particles may show fascinating physics and potential for spintronic devices. While skyrmions are observed in a wide range of materials, until now antiskyrmions were exclusive to materials with D2d symmetry. In this work, we show first and second-order antiskyrmions stabilized by magnetic dipole–dipole interaction in Fe/Gd-based multilayers. We modify the magnetic properties of the multilayers by Ir insertion layers. Using Lorentz transmission electron microscopy imaging, we observe coexisting antiskyrmions, Bloch skyrmions, and type-2 bubbles and determine the range of material properties and magnetic fields where the different spin objects form and dissipate. We perform micromagnetic simulations to obtain more insight into the studied system and conclude that the reduction of saturation magnetization and uniaxial magnetic anisotropy leads to the existence of this zoo of different spin objects and that they are primarily stabilized by dipolar interaction.

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