Zero Hysteresis in Shape-Memory TI-NI-X Films (X = CU, PD) Under Constraint

1999 ◽  
Vol 604 ◽  
Author(s):  
B. Winzek ◽  
E. Quandt
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Shape Memory ◽  
Dc Magnetron Sputtering ◽  
Hysteresis Width ◽  
Metallic Substrates ◽  
Shape Memory Actuators ◽  
Expansion Coefficients ◽  
The Difference ◽  
Hysteresis Properties

AbstractThe hysteresis of thin film shape memory actuators affects the frequency of actuators switching between martensite and austenite. Therefore the hysteresis properties of thin films of TiNi, Ti(Ni,Cu) and Ti(NiPd) deposited onto metallic substrates by DC-Magnetron sputtering have been investigated. The substrates have different expansion coefficients to establish biaxial tensile and compressive film stresses, respectively. The results show, that the hysteresis width is significantly affected by the stress state of the shape memory film and in principal depends on the temperature range of measurement. In contrast, the difference Af-Mf remains unchanged. In some alloys zero hysteresis width could be obtained.

Sputter-Deposited Shape-Memory Alloy Thin Films: Properties and Applications

MRS Bulletin ◽  
2002 ◽  
Vol 27 (2) ◽  
pp. 111-114 ◽  
Author(s):  
Akira Ishida ◽  
Valery Martynov
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Microelectromechanical Systems ◽  
Sputter Deposition ◽  
Bulk Materials ◽  
Shape Memory Actuators ◽  
Sputter Deposited ◽  
Memory Characteristics

AbstractShape-memory alloy (SMA) thin films formed by sputter deposition have attracted considerable attention in the last decade. Current intensive research demonstrates that unique fine microstructures are responsible for the superior shape-memory characteristics observed in thin films as compared with bulk materials. Simultaneously, much effort has been undertaken to develop and fabricate micro devices actuated by SMA thin films. This article reviews the research to date on shape-memory behavior and the mechanical properties of SMA thin films in connection with their peculiar microstructures. Promising applications such as microvalves are demonstrated, along with a focused discussion on process-related problems. All of the results indicate that thin-film shape-memory actuators are ready to contribute to the development of microelectromechanical systems.

Structural, Morphological and Adhesion Properties of Cofeb Thin Films Deposited by DC Magnetron Sputtering

2013 ◽  
Vol 802 ◽  
pp. 47-52
Author(s):  
Chuleerat Ibuki ◽  
Rachasak Sakdanuphab
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Magnetron Sputtering ◽  
Crystalline Structure ◽  
Glass Substrate ◽  
Intrinsic Stress ◽  
Dc Magnetron Sputtering ◽  
Adhesion Properties ◽  
Sputtering Power

In this work the effects of amorphous (glass) and crystalline (Si) substrates on the structural, morphological and adhesion properties of CoFeB thin film deposited by DC Magnetron sputtering were investigated. It was found that the structure of a substrate affects to crystal formation, surface morphology and adhesion of CoFeB thin films. The X-Ray diffraction patterns reveal that as-deposited CoFeB thin film at low sputtering power was amorphous and would become crystal when the power increased. The increase in crystalline structure of CoFeB thin film is attributed to the crystalline substrate and the increase of kinetic energy of sputtering atoms. Atomic Force Microscopy images of CoFeB thin film clearly show that the roughness, grain size, and uniformity correlate to the sputtering power and the structure of substrate. The CoFeB thin film on glass substrate shows a smooth surface and a small grain size whereas the CoFeB thin film on Si substrate shows a rough surface and a slightly increases of grain size. Sticky Tape Test on CoFeB thin film deposited on glass substrate indicates the adhesion failure with a high sputtering power. The results suggest that the crystalline structure of substrate affects to the atomic bonding and the sputtering power affects to intrinsic stress of CoFeB thin film.

scholarly journals Nanoscale Mechanical Properties of Nanoindented Ni48.8Mn27.2Ga24 Ferromagnetic Shape Memory Thin Film

Scanning ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
Xiaofei Fu ◽  
Chao Liu ◽  
Xili Lu ◽  
Xianli Li ◽  
Jingwei Lv ◽  
...  
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Martensitic Transformation ◽  
Magnetron Sputtering ◽  
Shape Memory ◽  
Room Temperature ◽  
Shape Recovery ◽  
Recovery Ratio ◽  
Dc Magnetron Sputtering ◽  
Ferromagnetic Shape Memory

The structure and nanoscale mechanical properties of Ni48.8Mn27.2Ga24 thin film fabricated by DC magnetron sputtering are investigated systematically. The thin film has the austenite state at room temperature with the L21 Hesuler structure. During nanoindentation, stress-induced martensitic transformation occurs on the nanoscale for the film annealed at 823 K for 1 hour and the shape recovery ratio is up to 85.3%. The associated mechanism is discussed.

The Use of BaF2 Buffer Layers for the Sputter-Deposition of Ticabacuo Thin-Film Superconductors

1989 ◽  
Vol 169 ◽  
Author(s):  
K.M. Hubbard ◽  
P.N. Arendt ◽  
D.R. Brown ◽  
D.W. Cooke ◽  
N.E. Elliott ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Sputter Deposition ◽  
Buffer Layers ◽  
X Ray Diffraction ◽  
Dc Magnetron Sputtering ◽  
X Ray ◽  
Film Substrate ◽  
Ion Backscattering ◽  
Scanning Electron

AbstractThin films of the Tl‐based superconductors often have relatively poor properties because of film/substrate interdiffusion which occurs during the anneal. We have therefore investigated the use of BaF2 as a diffusion barrier. TICaBaCuO thin films were deposited by dc magnetron sputtering onto MgO <100> substrates, both with and without an evaporation‐deposited BaF2 buffer layer, and post‐annealed in a Tl over‐pressure. Electrical properties of the films were determined by four‐point probe analysis, and compositions were measured by ion‐backscattering spectroscopy. Structural analysis was performed by X‐ray diffraction and scanning electron microscopy. The BaF2 buffer layers were found to significantly improve the properties of the TICaBaCuO thin films.

Measurement of the Thermal Conductivity and Heat Capacity of Freestanding Shape Memory Thin Films Using the 3ω Method

2008 ◽  
Vol 130 (10) ◽  
Author(s):  
Ankur Jain ◽  
Kenneth E. Goodson
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Shape Memory ◽  
Temperature Response ◽  
Thermal Response ◽  
Temperature Phase ◽  
Property Measurement ◽  
Low Temperature Phase

An accurate measurement of the thermophysical properties of freestanding thin films is essential for modeling and predicting thermal performance of microsystems. This paper presents a method for simultaneous measurement of in-plane thermal conductivity and heat capacity of freestanding thin films based on the thermal response to a sinusoidal electric current. An analytical model for the temperature response of a freestanding thin film to a sinusoidal heating current passing through a metal heater patterned on top of the thin film is derived. Freestanding thin-film samples of silicon nitride and nickel titanium (NiTi), a shape memory alloy, are microfabricated and characterized. The thermal conductivity of thin-film NiTi, which increases linearly between 243K and 313K, is 40% lower than the bulk value at room temperature. The heat capacity of NiTi also increases linearly with temperature in the low temperature phase and is nearly constant above 280K. The measurement technique developed in this work is expected to contribute to an accurate thermal property measurement of thin-film materials. Thermophysical measurements on NiTi presented in this work are expected to aid in an accurate thermal modeling of microdevices based on the shape memory effect.

FORMATION OF TRIANGULAR Cu MICROCRYSTALS IN Ti/Cu/Si THIN FILMS DURING ANNEALING

2018 ◽  
Vol 25 (05) ◽  
pp. 1850097
Author(s):  
QIJING LIN ◽  
WEIXUAN JING ◽  
ZHUANGDE JIANG ◽  
NA ZHAO ◽  
ZIRONG WU ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Rapid Thermal Annealing ◽  
Dc Magnetron Sputtering ◽  
Triangular Pyramid ◽  
Single Side ◽  
Surface Patterns ◽  
Cu Thin Film ◽  
Sputtering System

Sandwich stacked Ti/Cu/Si thin films were deposited on a single-side polished Si(111) substrate using DC magnetron sputtering system and annealed using a rapid thermal annealing (RTA) system. Complex dendritic patterns, whose branches are composed of Cu rods and triangular Cu microcrystals were obtained on Ti/Cu thin film annealed at 700[Formula: see text]C. The shape of one triangular Cu microcrystal is a truncated equilateral triangular pyramid with a flat top. Triangular Cu microcrystals grow in the number when Ti/Cu thin films are annealed at 800[Formula: see text]C. Experimental results show that anisotropy affects the growth of surface patterns and the top Ti capping layer works as a protection for the underlying Cu layer from oxidation.

Thin Film Depositions of CdTe Semiconductors on Amorphous and Single Crystal Substrates and Comparisons of their Properties

2010 ◽  
Vol 638-642 ◽  
pp. 2909-2914 ◽  
Author(s):  
Yuichi Sato ◽  
Tatsushi Kodate ◽  
Manabu Arai
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Substrate Temperature ◽  
Single Crystal ◽  
Photoluminescence Properties ◽  
Glass Substrates ◽  
Indium Doping ◽  
Sapphire Single Crystal ◽  
Cdte Thin Films ◽  
The Difference

Thin films of CdTe semiconductors were prepared on sapphire single crystal and quartz glass substrates by a vacuum evaporation method. Crystallinity and photoluminescence properties of the obtained CdTe thin films on the substrates were semi-quantitatively compared concerning the difference of the substrate materials. Dependences of the properties on the substrate temperature in the preparations and indium doping to the thin films were also investigated.

Effect of Anodizing Voltage on Anodic Titanium Dioxide (ATO) Growth Based on an Ethylene Glycol Solution Containing NH4F

2016 ◽  
Vol 872 ◽  
pp. 147-151
Author(s):  
Chayangkoon Mangkornkarn ◽  
Benjarong Samransuksamer ◽  
Mati Horprathum ◽  
Pitak Eiamchai ◽  
Apiluck Eiad-Ua ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Titanium Dioxide ◽  
Surface Morphology ◽  
Ethylene Glycol ◽  
Applied Voltage ◽  
Base Material ◽  
Dc Magnetron Sputtering ◽  
Anodization Process ◽  
Glycol Solution

We reported on the influence of applied voltage on the surface morphology of anodic titanium dioxide (ATO) thin films. At first, titanium (Ti) thin films were prepared by DC-magnetron sputtering for use as a base material in the anodization process. The titanium dioxide (TiO2) nanoporous ATO was fabricated by the anodization process from the Ti thin film, with different applied voltages from 20 V to 60 V in an electrolyte based on an ethylene glycol containing NH4F. Pore size distribution of ATO thin films can be varied from 20-50 nm by increasing the applied voltage, while the thickness of the film also increases. In addition, to observe the effect of time, the optimal condition of anodizing voltage was studied by increasing the anodizing time. The results clearly showed the nanoporous ATO over the films and the thickness of the nanoporous ATO is approximately 260 nm.

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