scholarly journals Ab initiostudy of spin-spiral noncollinear magnetism in a free-standing Fe(110) monolayer under in-plane strain

2012 ◽  
Vol 85 (13) ◽  
Author(s):  
Takahiro Shimada ◽  
Junichi Okuno ◽  
Takayuki Kitamura
Keyword(s):  
Plane Strain ◽  
Free Standing ◽  
Spin Spiral

Measuring the Mechanical Properties of Thin Metal Films by Means of Bulge Testing of Micromachined Windows

1994 ◽  
Vol 356 ◽  
Author(s):  
V. M. Paviot ◽  
J. J. Vlassak ◽  
W. D. Nix
Keyword(s):  
Residual Stress ◽  
Silicon Nitride ◽  
Yield Stress ◽  
Plane Strain ◽  
Metal Films ◽  
Nitride Film ◽  
Silicon Nitride Film ◽  
Free Standing ◽  
Plastic Properties ◽  
Bulge Testing

AbstractFree-standing films of gold and aluminum have been fabricated using standard micro-machining techniques. LPCVD silicon nitride films are deposited onto (100) silicon wafers. Square and rectangular silicon nitride membranes are made by anisotropic etching of the silicon substrates. Then, metal films are deposited onto the silicon nitride membranes by means of evaporation. Finally, the sacrificial silicon nitride film is etched away by means of reactive plasma etching, resulting in well-defined, square and rectangular metal membranes.Bulge testing of square windows allows one to determine the biaxial modulus of the film as well as the residual stress in it. Testing rectangular windows yields the plane-strain elastic modulus and the residual stress. Since deformation in rectangular membranes approaches plane-strain deformation, this geometry is ideal for studying the plastic properties of the metal films. Stress-strain curves can be readily determined from the load-deflection curves of rectangular membranes. The gold films have a biaxial modulus of 161±3 GPa and a plane-strain modulus of 105±5 GPa, slightly lower than the literature values for a (111) textured film. The yield stress of these films is approximately 231±17 MPa at 10−4% plastic strain. The elastic moduli of the aluminum films are 105±3 GPa and 76.4±0.7 GPa, respectively; the yield stress of these films is 187±30MPa.

Spin-spiral structures in free-standing Fe(110) monolayers

2006 ◽  
Vol 99 (8) ◽  
pp. 08N501 ◽  
Author(s):  
Kohji Nakamura ◽  
Naoki Mizuno ◽  
Toru Akiyama ◽  
Tomonori Ito ◽  
A. J. Freeman
Keyword(s):  
Free Standing ◽  
Spiral Structures ◽  
Spin Spiral

In-plane strain distribution in free-standing GaAs/InGaAs/GaAs single quantum well surface nanostructures on GaAs[001]

1999 ◽  
Vol 85 (3) ◽  
pp. 1524-1530 ◽  
Author(s):  
A. Ulyanenkov ◽  
T. Baumbach ◽  
N. Darowski ◽  
U. Pietsch ◽  
K. H. Wang ◽  
...  
Keyword(s):  
Quantum Well ◽  
Plane Strain ◽  
Strain Distribution ◽  
Single Quantum ◽  
Free Standing ◽  
Single Quantum Well ◽  
Surface Nanostructures

Body balance in a free-standing position in road and off-road cyclists

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
Paulina Hebisz ◽  
Rafal Hebisz ◽  
Marek Zaton
Keyword(s):  
Sagittal Plane ◽  
Standing Position ◽  
The Body ◽  
Free Standing ◽  
Body Balance ◽  
Eyes Closed ◽  
Road Cycling ◽  
Progressive Exercise ◽  
Before And After ◽  
Road Cyclists

AbstractBackground: The purpose of this study was to compare body balance in road and off-road cyclists, immediately before and after the racing season.Material/Methods: Twenty individuals participated in the study and they were divided into two groups: specialists in road-cycling (n = 10) and in off-road cycling (n = 10). Immediately before and after the five-month racing season stabilographic trials were carried out (at rest and after progressive exercise). In assessing body balance the distance and velocity of the centre shifts (in the anterior-posterior and left-right direction) were analysed. The tests were performed with the cyclists’ eyes open, eyes closed, and in feedback.Results: After the racing season, in the off-road cyclists’ group, distance and velocity of the centre of pressure shifts increased after a progressive exercise.Conclusions: In the off-road cyclists’ group the balance of the body in the sagittal plane deteriorated after the racing season. Moreover, after the racing season off-road cyclists were characterized by a worse balance of the body, compared to road cyclists

Wrinkling Poly(trimethylene 2,5-Furanoate) Free-standing Films: Nanostructure Formation and Physical Properties

2020 ◽  
Author(s):  
Michelina Soccio ◽  
Nadia Lotti ◽  
Andrea Munari ◽  
Esther Rebollar ◽  
Daniel E Martínez-Tong
Keyword(s):  
Irradiation Time ◽  
Polymer Surface ◽  
Laser Source ◽  
Free Standing ◽  
Force Microscopy ◽  
Nanostructure Formation ◽  
Physicochemical Changes ◽  
Angle Measurements ◽  
Atomic Force ◽  
Contact Angle Measurements

<p>Nanostructured wrinkles were developed on fully bio-based poly(trimethylene furanoate) (PTF) films by using the technique of Laser Induced Periodic Surface Structures (LIPSS). We investigated the effect of irradiation time on wrinkle formation using an UV pulsed laser source, at a fluence of 8 mJ/cm2. It was found that the pulse range between 600 and 4800 pulses allowed formation of periodic nanometric ripples. The nanostructured surface was studied using a combined macro- and nanoscale approach. We evaluated possible physicochemical changes taking place on the polymer surface after irradiation by infrared spectroscopy, contact angle measurements and atomic force microscopy. The macroscopic physicochemical properties of PTF showed almost no changes after nanostructure formation, differently from the results previously found for the terephthalic counterparts, as poly(ethyleneterephthalate), PET, and poly(trimethyleneterephthalate), PTT. The surface mechanical properties of the nanostructured PTF were found to be improved, as evidenced by nanomechanical force spectroscopy measurements. In particular, an increased Young’s modulus and higher stiffness for the nanostructured sample were measured. <br></p>

Ultrastrong, Free-Standing and Large Nanofilms of Pyrenearamid

2019 ◽  
Author(s):  
Amalia Rapakousiou ◽  
Alejandro López-moreno ◽  
Belén Nieto-Ortega ◽  
M. Mar Bernal ◽  
Miguel A. Monclús ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Building Block ◽  
Aromatic Polyamide ◽  
Free Standing ◽  
Spatial Confinement ◽  
Polymeric Structure ◽  
Reduced Modulus ◽  
Organizational Arrangement ◽  
Polycyclic Aromatic ◽  
Nanoscale Building Block

We introduce poly(1,6-pyrene terephthalamide) polymer (PPyrTA) as an aromatic polyamide analogue of poly(p-phenylene terephthalamide) (PPTA), also known as Kevlar®. This work shows that the incorporation of polycyclic aromatic pyrene moieties improves drastically the mechanical properties of the polymeric structure, increasing elastic nanoindentation-determined modulus and hardness by factors of 1.9 and 4.3, respectively. Liquid deprotonated dispersions of PPyrTA nanofibers were used as nanoscale building block for producing large-surface, free-standing polymer macroscopic nanofilms. This 2D assembly leads to further significant improvements in reduced modulus and hardness (more than twice) compared to the starting polymer macroscale fibres, due to a better re-organizational arrangement of the PPyrTA nanofibers in the nanofilms, formed under 2D spatial confinement.

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