Effect of Laser Energy Density on Surface Morphology, Microstructure, and Magnetic Properties of Selective Laser Melted Fe-3wt.% Si Alloys

2021 ◽  
Author(s):  
Shuohong Gao ◽  
Xingchen Yan ◽  
Cheng Chang ◽  
Eric Aubry ◽  
Min Liu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Energy Density ◽  
Surface Morphology ◽  
Laser Energy ◽  
Laser Energy Density ◽  
Microstructure And Magnetic Properties

Laser Energy Dependent Structure of Pulsed Laser Deposited Barium Dititanate Films

2009 ◽  
Vol 66 ◽  
pp. 183-186
Author(s):  
L. Li ◽  
Chuan Bin Wang ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Energy Density ◽  
Surface Morphology ◽  
Pulsed Laser Deposition ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Preferred Orientation ◽  
Laser Deposition ◽  
Laser Energy Density ◽  
Energy Dependent ◽  
Deposited Films

Barium dititanate (BaTi2O5) films were prepared on MgO (100) substrate by pulsed laser deposition under various laser energy densities. The effect of laser energy on crystallinity, orientation and surface morphology was investigated. The preferred orientation of the as-deposited films changes from (710) to (020) with decreasing laser energy, and the surface morphology is different depending on laser energy too. The b-axis oriented BaTi2O5 film could be obtained at the laser energy density of 2J/cm2, where the film shows a dense surface with an elongated granular texture.

scholarly journals A Controllability Investigation of Magnetic Properties for FePt Alloy Nanocomposite Thin Films

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 53
Author(s):  
Jian Yu ◽  
Tingting Xiao ◽  
Xuemin Wang ◽  
Xiuwen Zhou ◽  
Xinming Wang ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Energy Density ◽  
Magnetic Phase ◽  
Laser Energy ◽  
Pulsed Laser ◽  
Laser Energy Density ◽  
Soft Magnetic ◽  
Fept Alloy ◽  
Nanocomposite Thin Films

An appropriate writing field is very important for magnetic storage application of L10 FePt nanocomposite thin films. However, the applications of pure L10 FePt are limited due to its large coercivity. In this paper, the ratios of L10 and non-L10 phase FePt alloy nanoparticles in FePt/MgO (100) nanocomposite thin films were successfully tuned by pulsed laser deposition method. By adjusting the pulsed laser energy density from 3 to 7 J/cm2, the ordering parameter initially increased, and then decreased. The highest ordering parameter of 0.9 was obtained at the pulsed laser energy density of 5 J/cm2. At this maximum value, the sample had the least amount of the soft magnetic phase of almost 0%, as analyzed by a magnetic susceptibility study. The saturation magnetization decreased with the increase in the content of soft magnetic phase. Therefore, the magnetic properties of FePt nanocomposite thin films can be controlled, which would be beneficial for the magnetic applications of these thin films.

Fundamentals of radiation heat transfer in AlSi10Mg powder bed during selective laser melting

2019 ◽  
Vol 25 (9) ◽  
pp. 1506-1515 ◽  
Author(s):  
Pei Wei ◽  
Zhengying Wei ◽  
Zhne Chen ◽  
Jun Du ◽  
Yuyang He ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Energy Density ◽  
Negative Impact ◽  
Laser Energy ◽  
Melting Process ◽  
Laser Energy Density ◽  
Granular System ◽  
Laser Melting ◽  
Content Type ◽  
Powder Bed

Purpose This paper aims to study numerically the influence of the applied laser energy density and the porosity of the powder bed on the thermal behavior of the melt and the resultant instability of the liquid track. Design/methodology/approach A three-dimensional model was proposed to predict local powder melting process. The model accounts for heat transfer, melting, solidification and evaporation in granular system at particle scale. The proposed model has been proved to be a good approach for the simulation of the laser melting process. Findings The results shows that the applied laser energy density has a significantly influence on the shape of the molten pool and the local thermal properties. The relative low or high input laser energy density has the main negative impact on the stability of the scan track. Decreasing the porosity of the powder bed lowers the heat dissipation in the downward direction, resulting in a shallower melt pool, whereas pushing results in improvement in liquid track quality. Originality/value The randomly packed powder bed is calculated using discrete element method. The powder particle information including particle size distribution and packing density is taken into account in placement of individual particles. The effect of volumetric shrinkage and evaporation is considered in numerical model.

Effects of laser energy density on in situ formation of nano-graphite

2019 ◽  
Vol 48 (5) ◽  
pp. 506004
Author(s):  
刘孝谦 Liu Xiaoqian ◽  
骆 芳 Luo Fang ◽  
杜琳琳 Du Linlin ◽  
陆潇晓 Lu Xiaoxiao
Keyword(s):  
Energy Density ◽  
Laser Energy ◽  
Laser Energy Density ◽  
In Situ Formation

Considerations for Large Area Fabrication of Integrated a-Si and Poly-Si TFTs

1994 ◽  
Vol 336 ◽  
Author(s):  
P. Mei ◽  
G. B. Anderson ◽  
J. B. Boyce ◽  
D. K. Fork ◽  
M. Hack ◽  
...  
Keyword(s):  
Grain Size ◽  
Energy Density ◽  
Laser Energy ◽  
Gate Insulator ◽  
Laser Energy Density ◽  
Laser Crystallization ◽  
Large Area ◽  
Low Leakage ◽  
Threshold Voltages ◽  
Excellent Method

ABSTRACTThe combination of a-Si low leakage pixel TFTs with poly-Si TFTs in peripheral circuits provides an excellent method for reducing the number of external connections to large-area imaging arrays and displays. To integrate the fabrication of the peripheral poly-Si TFTs with the a-Si pixel TFTs, we have developed a three-step laser process which enables selective crystallization of PECVD a-Si:H. X-ray diffraction and transmission electron microscopy show that the polycrystalline grains formed with this three-step process are similar to those crystallized by a conventional one step laser crystallization of unhydrogenated amorphous silicon. The grain size increases with increasing laser energy density up to a peak value of a few Microns. The grain size decreases with further increases in laser energy density. The transistor field effect mobility is correlated with the grain size, increasing gradually with laser energy density until reaching its maximum value. Thereafter, the transistors suffer from leakage through the gate insulators. A dual dielectric gate insulator has been developed for these bottom-gate thin film transistors to provide the correct threshold voltages for both a-Si and poly-Si TFTs.

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