scholarly journals Crystallization Behavior and Thermal Analysis of CoFeB Thin Films

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Jiun-Yi Tseng ◽  
Yuan-Tsung Chen ◽  
Z. G. Chang ◽  
C. W. Wu ◽  
L. C. Yang
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Thermal Analysis ◽  
Thermal Properties ◽  
Crystallization Behavior ◽  
Glass Forming Ability ◽  
Dc Magnetron Sputtering ◽  
Glass Substrates ◽  
Glass Forming ◽  
Onset Crystallization Temperature

We examined two targets containing Co40Fe40B20and Co60Fe20B20. We deposited Co40Fe40B20and Co60Fe20B20monolayer thin films of various thicknesses on glass substrates through DC magnetron sputtering; the thicknesses ranged from 25 to 200 Å. The thermal properties of the Co40Fe40B20and Co60Fe20B20thin films were determined using a differential scanning calorimeter (DSC). The thermal properties included the glass transition temperature (Tg), onset crystallization temperature (Tx), and glass-forming ability, which were determined according to these values. Using the Kissinger formula revealed that the activation energy of the Co60Fe20B20with a thickness of 75 Å is the highest, implying that crystallization was the lowest and the Co60Fe20B20film showed anticrystallization properties. However, the energy of 75 Å Co40Fe40B20thin films was the lowest, which is opposite to that of Co60Fe20B20. This observation can be reasonably explained based on the concentration of Co or Fe. Therefore, a thickness of 75 Å is critical.

Glass Forming Ability and Thermal Properties of a Cu-Based Bulk Metallic Glass Microalloyed with Silicon

2007 ◽  
Vol 561-565 ◽  
pp. 1341-1344 ◽  
Author(s):  
Jason S.C. Jang ◽  
Y.C. Huang ◽  
C.H. Lee ◽  
I.S. Lee ◽  
L.J. Chang
Keyword(s):  
Activation Energy ◽  
Thermal Properties ◽  
Isothermal Annealing ◽  
Alloy System ◽  
Glass Forming Ability ◽  
Casting Method ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Glass Forming ◽  
Activation Energy Of Crystallization

The (Cu42Zr42Al8Ag8)100-xSix amorphous alloy rods, x =0 to 1, with 3 mm in diameter were prepared by Cu-mold drop casting method. The glass forming ability, thermal properties and microstructure evolution was studied by differential scanning calorimetry (DSC), and X-ray diffractometry (XRD). The XRD result reveals that these as-quenched (Cu42Zr42Al8Ag8)100-xSix alloy rods exhibit a broaden diffraction pattern of amorphous phase. The crystallization temperature and GFA (glass forming ability) of (Cu42Zr42Al8Ag8)100-xSix alloys increase with the silicon additions. The highest Trg (0.59) and γ value (0.405) occurred at the (Cu42Zr42Al8Ag8)99.75Si0.25 and (Cu42Zr42Al8Ag8)99.5Si0.5 alloy. In addition, both of the activation energy of crystallization and the incubation time of isothermal annealing for these (Cu42Zr42Al8Ag8)100-xSix alloys indicates that the (Cu42Zr42Al8Ag8)99.25Si0.75 alloy posses the best thermal stability among the (Cu42Zr42Al8Ag8)100-xSix alloy system.

Development of quaternary Fe–B–Y–Nb bulk glassy alloys with high glass-forming ability

2007 ◽  
Vol 22 (2) ◽  
pp. 471-477 ◽  
Author(s):  
Dong Ho Kim ◽  
Jin Man Park ◽  
Do Hyang Kim ◽  
Won Tae Kim
Keyword(s):  
Glass Phase ◽  
Crystallization Behavior ◽  
Alloy System ◽  
Glass Forming Ability ◽  
Maximum Diameter ◽  
Glass Forming ◽  
Glassy Alloys ◽  
The Stability ◽  
Nb Addition ◽  
Compressive Mechanical Property

The effects of niobium (Nb) addition on the glass-forming ability (GFA), crystallization behavior, and compressive mechanical property of iron (Fe)–boron (B)–yttrium (Y) alloys have been investigated. Among the (Fe71.2B24Y4.8)100−xNbx (x = 0, 2, 4, 6, 8) alloys investigated, (Fe71.2B24Y4.8)96Nb4 exhibits the highest GFA, enabling the formation of glassy rods with a maximum diameter of 7 mm, which is the largest among quaternary Fe-based alloys. The comparison of the crystallization behavior of the alloys shows that the formation of metastable Fe23B6 phase during crystallization in the (Fe71.2B24Y4.8)96Nb4 alloy can suppress the formation of other stable crystalline phases such as α-Fe, enhancing the stability of the glass phase. The present results show that the attainment of a significantly high GFA is possible even in a quaternary Fe-based alloy system by properly tailoring the competing crystalline phase by the modification of liquid chemistry.

scholarly journals Crystallization Behavior of Al70Fe12.5V12.5Nb5 Amorphous Alloy Formed by Mechanical Alloying

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 383 ◽  
Author(s):  
Xuan Liu ◽  
Xingfu Wang ◽  
Yongli Si ◽  
Xiaokang Zhong ◽  
Fusheng Han
Keyword(s):  
Amorphous Alloy ◽  
Mechanical Alloying ◽  
Amorphous Alloys ◽  
Crystallization Behavior ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Glass Forming Ability ◽  
Liquid Region ◽  
Application Field ◽  
Glass Forming

In this study, the formation and crystallization of the Al70Fe12.5V12.5Nb5 amorphous alloys has been investigated. The addition of Nb enhances the supercooled liquid region and glass forming ability of the Al-Fe-V amorphous alloys. The Al70Fe12.5V12.5Nb5 amorphous alloy exhibits two distinct crystallization steps and a large supercooled liquid region at more than 100 K. Kissinger and Ozawa analyses showed that the two activation energies for crystallization (Ex) were estimated to be 366.3 ± 23.9 and 380.5 ± 23.9 kJ/mol. Large supercooled liquid regions are expected to gain an application field of Al-based amorphous alloys.

AlSb THIN FILMS PREPARED BY DC MAGNETRON SPUTTERING AND ANNEALING

2008 ◽  
Vol 22 (14) ◽  
pp. 2275-2283 ◽  
Author(s):  
WEIDONG CHEN ◽  
LIANGHUAN FENG ◽  
ZHI LEI ◽  
JINGQUAN ZHANG ◽  
FEFE YAO ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
High Efficiency ◽  
Dark Conductivity ◽  
Aluminum Antimonide ◽  
Dc Magnetron Sputtering ◽  
Glass Substrates ◽  
Average Grain Size ◽  
P Type ◽  
20 Nm

Aluminum antimonide (AlSb) is thought to be a potential material for high efficiency solar cells. In this paper, AlSb thin films have been fabricated by DC magnetron sputtering on glass substrates. The sputtering target consists of aluminum and antimony, and the area ratio of Al to Sb is 7:3, which is derived from research into the relationship between the deposition rates of both the metals and sputtering power. XRD and AFM measurements show that the as-deposited films are amorphous, but become polycrystalline with an average grain size of about 20 nm after annealing in an argon atmosphere. From optical absorption measurements of annealed AlSb films, a band gap of 1.56 eV has been demonstrated. Hall measurements show that the films are p-type semiconductors. The temperature dependence of dark conductivity tested in vacuum displays a linear lnσ to 1/T curve, which indicates a conductivity activation energy of around 0.61 eV.

scholarly journals Preparation, Characterization, and Properties of Novel Ti-Zr-Be-Co Bulk Metallic Glasses

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 223 ◽  
Author(s):  
Pan Gong ◽  
Fangwei Li ◽  
Junsong Jin
Keyword(s):  
Corrosion Resistance ◽  
Metallic Glasses ◽  
Crystallization Behavior ◽  
Base Alloy ◽  
Bulk Metallic Glasses ◽  
Critical Diameter ◽  
Glass Forming Ability ◽  
Specific Strength ◽  
Glass Forming ◽  
Co Addition

We developed novel Ti-Zr-Be-Co bulk metallic glasses through Co addition based on a ternary Ti45Zr20Be35 alloy. By altering the alloying routes and alloying contents, the influence of Co alloying on glass-forming ability, thermal stability, thermoplastic formability, crystallization behavior, and corrosion resistance has been investigated systematically. It was found that the best alloying route for enhancing the glass-forming ability, thermoplastic formability, compressive plasticity, and corrosion resistance is to replace Be by Co. Ti45Zr20Be23Co12 possesses the largest critical diameter of 15 mm for glass formation. Ti45Zr20Be27Co8 possesses the highest thermoplastic formability which is comparable to that of Vitreloy alloys. Ti45Zr20Be25Co10 exhibits the largest room temperature plasticity of 15.7% together with a high specific strength of 3.90 × 105 Nm/kg. The addition of Co also strongly affects the crystallization behavior of the base alloy, resulting in a more complex crystallization process. The corrosion resistance of Ti-Zr-Be alloy in 1 mol/L HCl solution can also be enhanced by Co alloying. The related mechanisms have been explained in detail, which provide guidance for the composition design of Ti-based metallic glasses with improved properties.

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