Mechanisms of Grain Growth in Free-Standing Nanograined Gold Thin Films

2005 ◽  
Vol 907 ◽  
Author(s):  
J. A. Gregg ◽  
K Hattar ◽  
C H Lei ◽  
I M Robertson

AbstractRetention of the enhanced properties reported for nanograined metallic systems requires that the nanostructure be insensitive to temperature and deformation. In situ transmission electron microscopy annealing experiments were employed to investigate the structural changes associated with the formation of micron-sized grains in nanograined evaporated gold thin films. This abnormal grain growth occurs randomly throughout the film. Twinning but not dislocation slip occurs in the growing grains until the grain size is in the hundreds of nanometer range. The twins appear to hinder growth and for grain growth to continue the twins must either be annihilated or be able to grow with the grain concurrently.

Nanoscale ◽  
2017 ◽  
Vol 9 (35) ◽  
pp. 12835-12842 ◽  
Author(s):  
C. N. Shyam Kumar ◽  
Venkata Sai Kiran Chakravadhanula ◽  
Adnan Riaz ◽  
Simone Dehm ◽  
Di Wang ◽  
...  

In situ TEM analysis of the thermally induced graphitization and domain growth of free-standing nanocrystalline graphene thin films.


2004 ◽  
Vol 854 ◽  
Author(s):  
K. Hattar ◽  
J. Gregg ◽  
J. Han ◽  
T. Saif ◽  
I. M. Robertson

ABSTRACTIn situ transmission electron microscopy analysis is used to study the stability of nanograined and ultra-fine grained thin films at elevated temperatures. In the free-standing Au and Cu films, grain growth was dependent on annealing temperature and time with growth observed in both materials at temperatures greater than 373K. Both materials exhibited abnormal grain growth although it was more prevalent in Au than in Cu, which may be a consequence of pinning of the Cu grain boundaries by impurities. The formation and destruction of twins was observed to play a critical role in the grain growth, with the twins retarding the growth in gold, but not in Cu. In constrained Au films no grain growth was observed on annealing at temperatures below 636 K. At 636 K, the eutectic temperature, the microstructure transformed to the eutectic structure with the first stage being the annihilation of the grain structure.


Author(s):  
K. Hattar ◽  
A. Misra ◽  
M. R. F. Dosanjh ◽  
P. Dickerson ◽  
I. M. Robertson ◽  
...  

The failure of a cross-sectional 65 nm-thick copper and 150 nm-thick niobium multilayer thin film was investigated via an in situ transmission electron microscopy straining experiment. The fracture of the free-standing multilayer films was associated with confined dislocation slip within layers containing and preceding the crack tip. Four crack hindrance mechanisms were observed to operate during crack propagation: microvoid formation, crack deviation, layer necking, and crack blunting. Failure was observed to occur across and through the copper and niobium layers but never within the interfaces or grain boundaries. These results are discussed relative to the length-scale-dependent deformation mechanisms of nanoscale metallic multilayers.


Author(s):  
J. T. Sizemore ◽  
D. G. Schlom ◽  
Z. J. Chen ◽  
J. N. Eckstein ◽  
I. Bozovic ◽  
...  

Investigators observe large critical currents for superconducting thin films deposited epitaxially on single crystal substrates. The orientation of these films is often characterized by specifying the unit cell axis that is perpendicular to the substrate. This omits specifying the orientation of the other unit cell axes and grain boundary angles between grains of the thin film. Misorientation between grains of YBa2Cu3O7−δ decreases the critical current, even in those films that are c axis oriented. We presume that these results are similar for bismuth based superconductors and report the epitaxial orientations and textures observed in such films.Thin films of nominally Bi2Sr2CaCu2Ox were deposited on MgO using molecular beam epitaxy (MBE). These films were in situ grown (during growth oxygen was incorporated and the films were not oxygen post-annealed) and shuttering was used to encourage c axis growth. Other papers report the details of the synthesis procedure. The films were characterized using x-ray diffraction (XRD) and transmission electron microscopy (TEM).


1999 ◽  
Vol 564 ◽  
Author(s):  
K. Barmak ◽  
G. A. Lucadamo ◽  
C. Cabral ◽  
C. Lavoie ◽  
J. M. E. Harper

AbstractWe have found the dissociation behavior of immiscible Cu-alloy thin films to fall into three broad categories that correlate most closely with the form of the Cu-rich end of the binary alloy phase diagrams. The motivation for these studies was to use the energy released by the dissociation of an immiscible alloy, in addition to other driving forces commonly found in thin films and lines, to promote grain growth and texture evolution. In this work, the dissociation behavior of eight dilute (3.3 ± 0.5 at% solute) binary Cu-systems was investigated, with five alloying elements selected from group VB and VIB, two from group VillA, and one from group 1B. These alloying elements are respectively V, Nb, Ta, Cr, Mo, Fe, Ru and Ag. Several experimental techniques, including in situ resistance and stress measurements as well as in situ synchrotron x-ray diffraction, were used to follow the progress of solute precipitation in approximately 500 nm thick films. In addition, transmission electron microscopy was used to investigate the evolution of microstructure of Cu(Ta) and Cu(Ag). For all eight alloys, dissociation occurred upon heating, with the rejection of solute and evolution of microstructure and texture often occurring in multiple steps that range over several hundred degrees between approximately 100 and 900°C. However, in most cases, substantial reduction in resistivity of the films took place at temperatures of interest to metallization schemes, namely below 400°C.


2017 ◽  
Vol 19 (31) ◽  
pp. 20867-20880 ◽  
Author(s):  
David C. Bock ◽  
Christopher J. Pelliccione ◽  
Wei Zhang ◽  
Janis Timoshenko ◽  
K. W. Knehr ◽  
...  

Crystal and atomic structural changes of Fe3O4upon electrochemical (de)lithiation were determined.


ACS Nano ◽  
2016 ◽  
Vol 10 (1) ◽  
pp. 1475-1480 ◽  
Author(s):  
Qing Wang ◽  
Ryo Kitaura ◽  
Shoji Suzuki ◽  
Yuhei Miyauchi ◽  
Kazunari Matsuda ◽  
...  

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