Magnetocrystalline anisotropy and volume ratio of FePt grains with c-axes parallel to the film plane in FePt granular film with various grain boundary materials

2021 ◽  
Author(s):  
Takashi Saito ◽  
Kim Kong Tham ◽  
Ryosuke Kushibiki ◽  
Tomoyuki OGAWA ◽  
Shin SAITO
Keyword(s):  
Grain Boundary ◽  
Magnetocrystalline Anisotropy ◽  
Volume Ratio ◽  
Film Plane ◽  
Granular Film

scholarly journals ZnO Thin Film Transistor: Effect of Traps and Grain Boundaries

2018 ◽  
Vol 17 (1) ◽  
pp. 41-43
Author(s):  
A.A. Razak ◽  
W.H. Khoo ◽  
Suhana Mohamed Sultan
Keyword(s):  
Grain Boundary ◽  
Semiconductor Industry ◽  
High Surface ◽  
Thin Film Transistor ◽  
Volume Ratio ◽  
Poor Performance ◽  
High Resistivity ◽  
Sensing Applications ◽  
Two Factors ◽  
Temperature Deposition

Recently ZnO has drawn a lot of attention in semiconductor industry due to its interesting features. High exciton binding energy, high resistivity against radiation, high breakdown voltage, low temperature deposition are some of the interesting features of this material. Zinc oxide TFT device gains an increasing interest for its potential in sensing applications due to its biocompability, chemical stability and  simple fabrication process with various methods and high surface-to-volume ratio. However, ZnO TFT devices from previous work exhibited poor ION and field effect mobility. This work investigates the cause of its poor performance by focusing only two factors: traps and defects in the channel and grain boundary. The work was performed in Silvaco TCAD 2D simulator. It was found that a single grain boundary in the channel causes a reduction of the ION by 95%. The effect in the ION is less severe when traps and defects were introduced in the ZnO channel. The results can assist in optimizing the TFT device performance for sensing applications.

Is There a Critical Size in Nano Grained Metals for Ductile to Brittle Transition?

2004 ◽  
Author(s):  
Aman Haque ◽  
Taher Saif
Keyword(s):  
Grain Size ◽  
Grain Boundary ◽  
Critical Size ◽  
Volume Ratio ◽  
Metal Films ◽  
Metal Structures ◽  
Brittle Transition ◽  
Ductile To Brittle Transition ◽  
Metal Properties

Nanoscale metal films and electrodes are extensively used in today’s micro and nano electronics as well as nano mechanical systems. These metal structures are usually polycrystalline in nature with nano scale grains connected to each other by grain boundaries. The small size offers large grain boundary to volume ratio that is likely to affect the metal properties significantly. Here, we discuss the role of grain size and boundaries in determining the mechanical behavior of metals, such as elasticity and yielding.

Soft Magnetic Properties and Microstructures for the Fe Based Sputtered Films with High Bs

1991 ◽  
Vol 232 ◽  
Author(s):  
Migaku Takahashi ◽  
T. Shimatsu
Keyword(s):  
Magnetic Anisotropy ◽  
Magnetocrystalline Anisotropy ◽  
Film Plane ◽  
Initial Permeability ◽  
Physical Origin ◽  
Soft Magnetic ◽  
Magnetic Anisotropy Energy ◽  
Local Anisotropy ◽  
Sputtered Films ◽  
Sufficient Reduction

ABSTRACTPhysical origin of high initial permeability, μi, in Fe based films with large magnetocrystalline anisotropy and magnetostriction is systematically discussed in connection with the microstructure of the films. In order to decrease the local anisotropy fluctuation to determine μi in these films, decrease of effective magnetic anisotropy, Ueff, of each grain mainly caused by the sufficient reduction of grain size is required. Induced uniaxial magnetic anisotropy energy, Ku, in film plane plays an important role to decrease Ueff through the micromagnetic interaction. The ratio of Ueff /Ku proposed as the important key to analyse the magnetization process. The dependence of μi Ku is classified concerning for Ueff/Ku.

Crystallinity Dependence of Grain and Grain Boundary Strength of a Bicrystal Structure of Copper

2020 ◽  
Author(s):  
Ken Suzuki ◽  
Yiqing Fan ◽  
Yifan Luo
Keyword(s):  
Thin Films ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Defect Density ◽  
Volume Ratio ◽  
Md Simulations ◽  
Atomic Diffusion ◽  
Strength And Deformation ◽  
Electroplated Copper ◽  
Boundary Strength

Abstract Electroplated copper thin films often contain porous grain boundaries and the volume ratio of porous grain boundaries in the copper thin films is much larger than that in bulk copper. Thus, the lifetime of the interconnection components fabricated by electroplating is strongly dominated by the strength of grain boundaries because final fracture caused by the acceleration of atomic diffusion during electromigration (EM) occurs at grain boundaries in polycrystalline interconnections. It is important, therefore, to quantitatively evaluate the grain boundary strength of electroplated copper films for estimating the lifetime of the interconnection in order to assure the product reliability. In this study, relationship between the strength and crystallinity of electroplated copper thin films was investigated experimentally and theoretically. In order to investigate the relationship between the strength and grain boundary quality, molecular dynamics (MD) simulations were applied to analyze the deformation behavior of a bicrystal sample and its strength. The variation of the strength and deformation property were attributed to the higher defect density around grain boundaries.

Effect of Amorphous Phase on Mechanical Properties of SiC/Cu Composites

2014 ◽  
Vol 602-603 ◽  
pp. 586-589
Author(s):  
Bing Sun ◽  
Bing Bing Fan ◽  
Chen Yang Wang ◽  
Bin Bin Wang ◽  
Wen Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Grain Boundary ◽  
Vickers Hardness ◽  
Glassy Phase ◽  
Bending Strength ◽  
Testing Machine ◽  
Volume Ratio ◽  
Apparent Porosity ◽  
Hardness Tester ◽  
Coating Method

In this study, glassy phase is formed by SiO2-K2O addition to serve as amorphous grain boundary transition layer. SiC (SiO2-K2O) / Cu composite material were prepared by two-step coating method and hot pressing sintered below 770°C, 30MPa for 1.5h, using α-SiC as main reinforced phase, SiO2-K2O as grain boundary and Cu as matrix. The Cu-SiC volume ratio was 75:25. The SiO2contents were 5vol.%, 10vol.%, 15vol.%, 20vol.% and 25vol.% of the total volume of the SiC / Cu. XRD and SEM techniques were used to characterize the composite particles and the sintered compacts; Archimedes method, Vickers hardness tester, universal testing machine to test the apparent porosity of the composite materials, the Vickers hardness and the bending strength, respectively. The results showed that with increasing of glassy phase contents, the Vickers hardness and the bending strength first rise and then drop, at the same time, it shows the opposite tendency for the apparent porosity. The sintering samples with the SiO2content of 15vol.% have the optimum mechanical properties, the Vickers hardness reached 1.49 GPa, and the bending strength was close to 235 MPa.

FIB/SEM Applied to Quantitative 3D Analysis of Precipitates in Ni-Ti

2011 ◽  
Vol 172-174 ◽  
pp. 1284-1289
Author(s):  
Shan Shan Cao ◽  
Minoru Nishida ◽  
Dominique Schryvers
Keyword(s):  
Martensitic Transformation ◽  
Aspect Ratio ◽  
Grain Boundary ◽  
Volume Ratio ◽  
Central Plane ◽  
3D Analysis ◽  
Heterogeneous Distribution ◽  
Heterogeneous Microstructure ◽  
Dual Beam

Ni4Ti3 precipitates with a heterogeneous distribution growing in a polycrystalline Ni50.8Ti49.2 alloy have been investigated in a Dual-Beam FIB/SEM system. The volume ratio, mean volume, central plane diameter, thickness, aspect ratio and sphericity of the precipitates in the grain interior as well as near to the grain boundary were measured or calculated. The morphology of the precipitates was classified according to the Zingg scheme. The multistage martensitic transformation occurring in these kinds of samples is interpreted in view of the data of this heterogeneous microstructure of matrix and precipitates.

Reversible Force-Resistivity Behavior of Thin Films of the TTF-Tcnq Family

1996 ◽  
Vol 436 ◽  
Author(s):  
W. Vollmann ◽  
H.-U. Sonntag
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Potential Barrier ◽  
Film Plane ◽  
Barrier Width ◽  
Dependent Potential ◽  
Sample Resistance

AbstractThe electrical properties of vacuum sublimed thin films of TTF-TCNQ and its derivatives mainly are determined by electron barriers at grain boundaries. The electrical conductivity is thermal activated and exhibits a significant dependence on a force acting perpenticularly to the film plane. The sample resistance R decreases continiously with increasing force F. TCNQ thin films on steel show a similar R-F relation. The effect has been observed already at forces of 1 N, but also up to about 60 kN. An explanation of these phenomena is given by a grain boundary limited hopping mechanism with pressure dependent potential barrier width and height. Morphology investigations by SEM support the model.

Grain Boundary Curvature in Polycrystalline Metallic Thin Films

2000 ◽  
Vol 615 ◽  
Author(s):  
Alexander H. King ◽  
Rakesh Mangat ◽  
Kwame Owusu-Boahen
Keyword(s):  
Thin Films ◽  
Grain Boundary ◽  
Film Thickness ◽  
Sheet Thickness ◽  
Film Plane ◽  
Thickness Effect ◽  
Metallic Thin Films ◽  
Boundary Curvature ◽  
Grain Boundary Grooves

ABSTRACTWell-annealed thin films are typically observed to exhibit mean grain diameters that are approximately equal to the film thickness. The standard explanation of this “sheet thickness effect” is that it results from a balance of grain boundary curvature in two different directions which, in turn, results from pinning at grain boundary grooves. TEM experiments have been performed to assess this model, and it is found that the predicted curvature about axes in the film plane is absent. Alternate explanations of the sheet thickness effect are considered.

scholarly journals Surface Segregation in Multicomponent Clusters

2005 ◽  
Vol 887 ◽  
Author(s):  
Peter A. Dowben ◽  
Ning Wu ◽  
Natalie Palina ◽  
Hartwig Modrow ◽  
Robert Müller ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Barium Ferrite ◽  
Surface Segregation ◽  
Boundary Segregation ◽  
Volume Ratio ◽  
Grain Boundary Segregation ◽  
Solid Samples ◽  
Atomic Coordination ◽  
Small Clusters ◽  
Theory And Experiment

ABSTRACTNanostructured materials are not immune from surface segregation, as can be shown for solid samples made from nanosized BaFe12−2xCoxTixO19 barium ferrite particles and a variety of free clusters. Both theory and experiment provide ample demonstration that very limited dimensions of very small clusters does not necessarily impart stability against surface and grain boundary segregation. In fact, with the larger surface to volume ratio in small clusters and lower average atomic coordination, we anticipate that compositional instabilities in small clusters will readily occur.

Noncollinear magnetism and enhancement of magnetocrystalline anisotropy at the Σ3(111) grain boundary in ferromagnetic Fe

2004 ◽  
Vol 84 (24) ◽  
pp. 4974-4976
Author(s):  
Kohji Nakamura ◽  
Tomonori Ito ◽  
A. J. Freeman ◽  
Lieping Zhong ◽  
Juan Fernandez-de-Castro
Keyword(s):  
Grain Boundary ◽  
Magnetocrystalline Anisotropy
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