Effects of DC Bias on the Thermal Stability of DC In-Line Sputtered CoCrTa/Cr Thin Film Media

1998 ◽  
Vol 517 ◽  
Author(s):  
J. P. Wang ◽  
L. P. Tan ◽  
T. Y. F. Liew ◽  
T. S. Low ◽  
H. L. Wong ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Stability ◽  
Magnetic Anisotropy ◽  
Bias Voltage ◽  
Viscosity Coefficient ◽  
Substrate Bias Voltage ◽  
Dc Bias ◽  
The Law ◽  
Thermal Stability Of ◽  
Magnetic Hardness

AbstractThe effects of DC bias on the thermal stability and magnetic anisotropy of CoCrTa/Cr thin film media fabricated by using a DC in-line sputtering machine is presented in this paper. In sputtering, a negative DC bias voltage, varying from 0 to 400 V, was applied for the CoCrTa layer. The coercivity was observed to increase almost linearly from 1800 to 2300 Oe for negative bias voltage from 0 to 400V. The thermal stability of these media was studied by measuring the time decay of remanent magnetization under various reverse magnetic fields. The maximum value of the magnetic viscosity coefficient, which happens around remanent coercivity of each samples, decreases with increasing substrate bias voltage. This implies an improvement in the thermal stability of the CoCrTa/Cr thin film media. The magnetic anisotropy constants were measured using both a torque magnetometer and a vibrating sample magnetometer. The magnetic anisotropy measured using torque magnetometer decreases, while that measured using the method of the law of approach to saturation was found to be almost constant, with increasing bias voltage. The activation volumes decreased with increasing bias voltage. The magnetic hardness coefficient determined using the law of approach to saturation, indicating the number of in-depth defects in the CoCrTa layer, increased with increasing bias voltage. The internal stress in these films measured using X-ray diffractometer also supported the existence of in-depth defects. The pinning of the rotation of magnetization by these defects in the magnetic grains maybe responsible for the improvement of thermal stability.

Improvement of Thermal Stability of ZrB2/Si3N4 Coatings as High-Temperature Solar Selective Absorbers

2014 ◽  
Vol 521 ◽  
pp. 581-585
Author(s):  
Yao Ming Sun ◽  
Xiu Di Xiao ◽  
Guan Qi Chai ◽  
Gang Xu ◽  
Bin Xiong ◽  
...  
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
High Temperature ◽  
Substrate Temperature ◽  
Bias Voltage ◽  
X Ray Diffraction ◽  
Substrate Bias Voltage ◽  
X Ray ◽  
Deposition Parameters ◽  
Thermal Stability Of

ZrB2 thin films were prepared by DC magnetron sputtering technique. The microstructure, thermal stability and optical properties of thin films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and spectrophotometer. The compactness of ZrB2 thin films was studied to improve the thermal stability by optimizing the deposition parameters. The compactness and thermal stability of the coatings were improved with the increase of substrate temperature. However, these properties of the coatings were enhanced firstly and then weakened with the increase of substrate bias voltage. The selectivity of sample deposited at high substrate temperature and suitable bias voltage degraded slightly after annealing at 500 °C/100 h in air. This provided a new way to improve the thermal stability of high-temperature solar selective absorber.

Influence of the substrate bias on the size and thermal stability of grains in magnetron-sputtered nanocrystalline Ag films

2005 ◽  
Vol 20 (4) ◽  
pp. 1071-1080 ◽  
Author(s):  
K. Pagh Almtoft ◽  
J. Bøttiger ◽  
J. Chevallier ◽  
N. Schell ◽  
R.M.S. Martins
Keyword(s):  
Thermal Stability ◽  
Bias Voltage ◽  
Ex Situ ◽  
Substrate Bias ◽  
X Ray Diffraction ◽  
Substrate Bias Voltage ◽  
One Dimensional ◽  
X Ray ◽  
Pole Figures ◽  
Thermal Stability Of

The nanostructural evolution during heat treatments of direct-current magnetron-sputtered Ag films, deposited at room temperature at different substrate bias voltages, was experimentally studied. A growth chamber equipped with a magnetron and Kapton windows for in-situ x-ray diffraction was mounted on a six-circle goniometer at a synchrotron beam line. Bragg–Brentano x-ray diffraction was used to monitor the (111) Bragg peak during thermal annealing of the Ag films. In addition, to investigate the 〈111〉 fiber texture, one-dimensional pole figures were measured ex situ. The thermal stability of the nanostructure was sensitively dependent on the substrate bias voltage. Increasing the bias voltage resulted in significantly lower rates of grain growth, which we ascribe mainly to the formation of Ar bubbles. Furthermore, the grain size in the as-deposited films decreased with increasing bias voltage while the width of the one-dimensional pole figures increased.

Effect of Substrate Bias Voltage on the Thermal Stability of Cu/Ta/Si Structures Deposited by Ion Beam Deposition

2003 ◽  
Vol 42 (Part 1, No. 5A) ◽  
pp. 2780-2785 ◽  
Author(s):  
Jae-Won Lim ◽  
Kouji Mimura ◽  
Kiyoshi Miyake ◽  
Mutsuo Yamashita ◽  
Minoru Isshiki
Keyword(s):  
Thermal Stability ◽  
Bias Voltage ◽  
Ion Beam ◽  
Substrate Bias ◽  
Substrate Bias Voltage ◽  
Ion Beam Deposition ◽  
Thermal Stability Of ◽  
Beam Deposition

Thermal stability of PECVD W-B-N thin film as a diffusion barrier

1997 ◽  
Author(s):  
YongTae Kim ◽  
Dong J. Kim ◽  
Chang W. Lee ◽  
Jong-Wan Park
Keyword(s):  
Thin Film ◽  
Thermal Stability ◽  
Diffusion Barrier ◽  
Thermal Stability Of

Intrinsic Thermal Stability of Anisotropic Thin-Film Superconductors

1990 ◽  
Vol 112 (1) ◽  
pp. 10-15 ◽  
Author(s):  
M. I. Flik ◽  
C. L. Tien
Keyword(s):  
Thin Film ◽  
Thermal Stability ◽  
Stability Criterion ◽  
High Temperature Superconductors ◽  
Stability Criteria ◽  
Anisotropic Thermal Conductivity ◽  
Operating Current ◽  
Released Energy ◽  
The Stability ◽  
Thermal Stability Of

Intrinsic thermal stability denotes a situation where a superconductor can carry the operating current without resistance at all times after the occurrence of a localized release of thermal energy. This novel stability criterion is different from the cryogenic stability criteria for magnets and has particular relevance to thin-film superconductors. Crystals of ceramic high-temperature superconductors are likely to exhibit anisotropic thermal conductivity. The resultant anisotropy of highly oriented films of superconductors greatly influences their thermal stability. This work presents an analysis for the maximum operating current density that ensures intrinsic stability. The stability criterion depends on the amount of released energy, the Biot number, the aspect ratio, and the ratio of the thermal conductivities in the plane of the film and normal to it.

Thermal stability of the in-plane magnetic anisotropy and the coercivity of nanocrystalline CoFeNi films

2003 ◽  
Vol 266 (3) ◽  
pp. 251-257 ◽  
Author(s):  
E.H. du Marchie van Voorthuysen ◽  
F.T. ten Broek ◽  
N.G. Chechenin ◽  
D.O. Boerma
Keyword(s):  
Thermal Stability ◽  
Magnetic Anisotropy ◽  
Thermal Stability Of

Improving the stabilities of organic solar cells via employing a mixed cathode buffer layer

2021 ◽  
Vol 95 (3) ◽  
pp. 30201
Author(s):  
Xi Guan ◽  
Yufei Wang ◽  
Shang Feng ◽  
Jidong Zhang ◽  
Qingqing Yang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thermal Stability ◽  
Solar Cells ◽  
Mixed Layer ◽  
Organic Solar Cells ◽  
Buffer Layers ◽  
Commercial Development ◽  
Conversion Efficiencies ◽  
Thermal Stability Of ◽  
Cathode Buffer Layers

Organic solar cells (OSCs) have been fabricated using cathode buffer layers based on bathocuproine (BCP) and 4,4'-N,N'-dicarbazole-biphenyl (CBP). It is found that despite nearly same power conversion efficiencies, the bilayer of BCP/CBP shows increased thermal stability of device than the monolayer of BCP, mostly because upper CBP thin film stabilizes under BCP thin film. The mixed layer of BCP:CBP gives slightly decreased efficiency than BCP and BCP/CBP, mostly because the electron mobility of the OSC using BCP:CBP is decreased than those using BCP and BCP/CBP. However, the BCP:CBP increases thermal stability of device than BCP and BCP/CBP, ascribed to that the BCP and CBP effectively inhibit reciprocal tendencies of crystallizations in the mixed layer. Moreover, the BCP:CBP improves the light stability of device than the BCP and BCP/CBP, because the energy transfer from BCP to CBP in in the mixed layer effectively decelerates the photodegradation of BCP. We provide a facial method to improve the stabilities of cathode buffer layers against heat and light, beneficial to the commercial development of OSCs.

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