scholarly journals Annealing effect on temperature stability and mechanical stress at the “CdxPb1−xS film – substrate” interface

2020 ◽  
Vol 7 (4) ◽  
pp. 250-258
Author(s):  
L. N. Maskaeva ◽  
A. D. Kutyavina ◽  
A. V. Pozdin ◽  
B. N. Miroshnikov ◽  
I. N. Miroshnikova ◽  
...  

The article establishes the upper temperature steadiness limit of СdxPb1-xS supersaturated solid solutions obtained by chemical bath deposition. СdxPb1-xS (x = 0.06; 0.122; 0.176) and (x = 0.02–0.05) films remained stable under the heating up to 405–410 and 450 K, respectively. SEM studies have shown that heating of СdxPb1-xS films (x = 0.02–0.05) to 620 K leads to the structure destruction. Internal mechanical compressive stresses at the "СdxPb1-xS film-substrate" interface was calculated in the range of 300–900 K for the first time ever, the highest values reached 2000–2750 kN/m2 for a number of the films compositions. In contrast to solid solutions, the expansion stresses up to 100 kN/m2 were derived for the CdS layer at 900 K. The obtained temperature steadiness boundaries and the mechanical stresses of СdxPb1-xS films must be taken into account in the development of photonic devices based on such materials.

2003 ◽  
Vol 779 ◽  
Author(s):  
T. John Balk ◽  
Gerhard Dehm ◽  
Eduard Arzt

AbstractWhen confronted by severe geometric constraints, dislocations may respond in unforeseen ways. One example of such unexpected behavior is parallel glide in unpassivated, ultrathin (200 nm and thinner) metal films. This involves the glide of dislocations parallel to and very near the film/substrate interface, following their emission from grain boundaries. In situ transmission electron microscopy reveals that this mechanism dominates the thermomechanical behavior of ultrathin, unpassivated copper films. However, according to Schmid's law, the biaxial film stress that evolves during thermal cycling does not generate a resolved shear stress parallel to the film/substrate interface and therefore should not drive such motion. Instead, it is proposed that the observed dislocations are generated as a result of atomic diffusion into the grain boundaries. This provides experimental support for the constrained diffusional creep model of Gao et al.[1], in which they described the diffusional exchange of atoms between the unpassivated film surface and grain boundaries at high temperatures, a process that can locally relax the film stress near those boundaries. In the grains where it is observed, parallel glide can account for the plastic strain generated within a film during thermal cycling. One feature of this mechanism at the nanoscale is that, as grain size decreases, eventually a single dislocation suffices to mediate plasticity in an entire grain during thermal cycling. Parallel glide is a new example of the interactions between dislocations and the surface/interface, which are likely to increase in importance during the persistent miniaturization of thin film geometries.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Denis V. Novitsky ◽  
Dmitry Lyakhov ◽  
Dominik Michels ◽  
Dmitrii Redka ◽  
Alexander A. Pavlov ◽  
...  

AbstractUnique and flexible properties of non-Hermitian photonic systems attract ever-increasing attention via delivering a whole bunch of novel optical effects and allowing for efficient tuning light-matter interactions on nano- and microscales. Together with an increasing demand for the fast and spatially compact methods of light governing, this peculiar approach paves a broad avenue to novel optical applications. Here, unifying the approaches of disordered metamaterials and non-Hermitian photonics, we propose a conceptually new and simple architecture driven by disordered loss-gain multilayers and, therefore, providing a powerful tool to control both the passage time and the wave-front shape of incident light with different switching times. For the first time we show the possibility to switch on and off kink formation by changing the level of disorder in the case of adiabatically raising wave fronts. At the same time, we deliver flexible tuning of the output intensity by using the nonlinear effect of loss and gain saturation. Since the disorder strength in our system can be conveniently controlled with the power of the external pump, our approach can be considered as a basis for different active photonic devices.


2014 ◽  
Vol 116 (19) ◽  
pp. 193511 ◽  
Author(s):  
G. P. Lindberg ◽  
T. O'Loughlin ◽  
N. Gross ◽  
A. Mishchenko ◽  
A. Reznik ◽  
...  

2000 ◽  
Vol 655 ◽  
Author(s):  
Jung-Hyuk Koh ◽  
S.I. Khartsev ◽  
Alex Grishin ◽  
Vladimir Petrovsky

AbstractFor the first time AgTa0.38Nb0.62O3 (ATN) films have been grown on the La0.7Sr0.3CoO3 (LSCO)/LaAlO3 single crystal as well as onto Pt80Ir20 (PtIr) polycrystalline substrate. Comprehensive X-ray diffraction analyses reveal epitaxial quality of ATN and LSCO films on the LaAlO3(001) substrate, while ATN/PtIr films have been found to be (001) preferentially oriented. Dielectric spectroscopy performed for ATN films and bulk ceramics in a wide temperature range 77 to 420 K shows the structural monoclinic M1-to-monoclinic M2 phase transition occurs in films at the temperature 60 °C lower than in ceramics. The tracing of the ferroelectric hysteresis P-E loops indicates the ferroelectric state in ATN films at temperatures below 125 K and yields remnant polarization of 0.4 μC/cm2 @ 77 K. Weak frequency dispersion, high temperature stability of dielectric properties as well as low processing temperature of 550 °C make ATN films to be attractive for various applications.


2012 ◽  
Vol 116 (22) ◽  
pp. 12149-12155 ◽  
Author(s):  
Shirly Borukhin ◽  
Cecile Saguy ◽  
Maria Koifman ◽  
Boaz Pokroy

1981 ◽  
Vol 7 ◽  
Author(s):  
J. S. Williams ◽  
K. T. Short

ABSTRACTHigh resolution Rutherford backscattering and channeling techniques have been used to investigate the formation and stability of supersaturated solid solutions of As, Sb, In, Pb, Tℓ and Bi implants in (100) silicon. In all cases nearsubstitutional solid solubilities far exceeding maximum equilibrium solubility limits can be achieved by furnace annealing at temperatures ≤ 600°C. Details of the recrystallisation process indicate that the maximum impurity concentration which can be incorporated onto silicon lattice sites may be controlled by impurity size and associated strain effects at the amorphous-crystal boundary during epitaxial regrowth.


1992 ◽  
Vol 280 ◽  
Author(s):  
K. S. Chandra Sekhar ◽  
A. K. Ballal ◽  
L. Salamanca-Riba ◽  
D. L. Partin

ABSTRACTHeteroepitaxial growth of indium arsenide films on indium phosphide substrates is being actively pursued since the electronic properties of these films make them promising materials for optoelectronic and other high speed devices. The various structural aspects of the film that affect their electronic properties are structural defects like dislocations, film-substrate interface roughness and chemical inhomogeneities. In InAs films, electrons accumulate at the film-air interface, making surface morphology an important factor that decides the electronic properties. The InAs films used in this study were grown on InP substrates by metal organic vapor deposition, at different temperatures. A higher growth temperature not only resulted in poor surface morphology of the film, but also created a rough film-substrate interface. However, at all deposition temperatures, the film-substrate interfaces are sharp. At lower growth temperature, the interfaces were flat. Films grown at lower temperatures had good surface morphology and a flat and shaip heterointerface.


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