Nanocomposites and nanomaterials

Synergy of the effect of temperature and force field on stability and lifetime of nanosized elements consisting of one- and two-dimensional nanostructures
Kotrechko Sergiy1,2, Timoshevskii Andriy1, Kolyvoshko Eugene3 ,
Stetsenko Nataliya1 , Matviychuk Yuriy1
1 G.V. Kurdyumov Institute for Metal Physics, National Academy of Sciences of Ukraine, 36, Academician Vernadsky Blvd., Kyiv-03680, Ukraine.
E-mail: natusjaimp@gmail.com
2 National Technical University of Ukraine “Igor Sikorsky Kyiv Polytechnic Institute” 37, Peremohy Ave. UA-03056 Kyiv, Ukraine
3 Taras Shevchenko Kyiv National University, 60, Volodymyrska Str., Kyiv-01601, Ukraine

Current trend of transition to practical use of nanoelements requires to study mechanisms that govern their lifetime under conditions of combined action of such factors as temperature and mechanical load. This is crucially important for straintronics elements, as they involve governing the functional properties of nanoelements by deforming them. Failure mechanism at these conditions is a fluctuation-induced interatomic bond break under the action of a force field. Usually, in this case, Arrhenius reaction theory is utilised to predict the lifetime of a macro-sized solid, in which the height of the barrier is a linear function of the magnitude of applied force. In Russian-language literature, this approach is called Zhurkov's theory.
The report shows that a specific feature of the mechanism that governs the lifetime of nanosized elements, consisting of a combination of one- and two-dimensional structures, is the synergy of temperature and force field. This synergy is manifested in a significant (by many orders of magnitude) fall in the lifetime of nanoelements. Synergy mechanism is that under certain conditions, thermally induced fluctuations of interatomic distance act as a trigger, which initiates release of the energy of elastic deformations accumulated in the nanoelement, which is spent on the work of contact bonds breaking. A fluctuation model of nanoelement failure is proposed, which enables to describe quantitatively the phenomenon of synergy of temperature and force field. Based on the results of DFT-calculations, the suggested model shows the existence of two mechanisms of contact bond break, namely - "low-energy" and "high-energy". This causes the existence of two regions in the lifetime dependence on the magnitude of applied force, which differ in the nature of this dependence. By the example of carbyne-graphene nanoelements, consisting of a combination of graphene sheets and a carbyne chain, the ranges of both temperature and applied force are ascertained at which it is possible to employ these nanoelements. 

1.	Kotrechko S., Timoshevskii A., Kolyvoshko E., Matviychuk Yu., and Stetsenko N. Thermomechanical stability of carbyne-based nanodevice // Nanoscale Res Lett. - 2017. - 12:327 P. 1-8.
2.	Kotrechko S., Timoshevskii A., Kolyvoshko E., Matviychuk Yu., Stetsenko N., and Zhang B. Lifetime of carbyne-based nanodevices: size and “even-odd” effects // Eur Phys J Plus. – 2019.- 134: 182 P. 1-10.