Temperature–pressure-induced solid–solid 〈100〉 to 〈110〉 reorientation in FCC metallic nanowire: a molecular dynamic study

Abstract

Atomistic simulation of initial <100> oriented FCC Cu nanowires shows a novel coupled temperature-pressure dependent reorientation from <100> to <110> phase. A temperature-pressure-induced solid-solid <100> to <110> reorientation diagram is generated for Cu nanowire with varying cross-sectional sizes. A critical pressure is reported for Cu nanowires with varying cross-sectional sizes, above which an initial <100> oriented nanowire shows temperature independent reorientation into the <110> phase. The effect of surface stresses on the <100> to <110> reorientation is also studied. The results indicate that above a critical cross-sectional size for a given temperature-pressure, <100> to <110> reorientation is not possible. It is also reported here that for a given applied pressure, an increase in temperature is required for the <100> to <110> reorientation with increasing cross-sectional size of the nanowire. The temperature-pressure-induced solid-solid <100> to <110> reorientation diagram reported in the present paper could further be used as guidelines for controlling the reorientations/shape memory in nano-scale applications of FCC metallic nanowires.

Crystallographic input data for (001)-, (110)- and (111)-oriented superlattices

“…It is well known that the crystal orientations have a significant impact on their properties and their potential applications. They can be generated artificially during the growth process but they can also occur naturally since a change of orientation can be induced by temperature or pressure (Sutrakar et al, 2012). The study of the orientation effect on superlattices and/ or quantum wells is a well documented topic and is still of actuality and importance (Kajikawa, 2012;Assa Aravindh et al, 2012).…”

Surface-induced structural transformation in nanowires

“…Hence, surface effects are dominant factors affecting the structure of nanowires and can even induce thorough structural transition. On the heels of these discoveries, other interesting materials properties such as surfaceinduced lattice reorientation, martensitic phase transformation (MT), pseudo-elastic behavior, and shape memory effects (SMEs) have been studied and observed from fcc [14,[19][20][21][22][23]28,[63][64][65][66][67][68][69][70][71][72][73][74][75], bcc [76][77][78][79][80][81][82], and hcp [83,84] single-element, layered composite [85][86][87][88][89], intermetallic alloy [90][91][92][93][94][95], and even metal oxide [96][97][98][99][100] or nitride [101] compound nanowires. The reversible strain can be as high as 40-70% and is much lar...…”

“…With regard to the phase transformation from fcc to bct in Ag nanorods, the overall volume decreases by about 25% and hence, the increase in pressure should favor the formation of the bct phase [64]. Sutrakar et al [73] have studied the combined effects of the temperature, pressure, and size on the <1 0 0> to <1 1 0> reorientation in Cu nanowires. In their model, the pressure along the length axis of the nanowire is increased at a rate of 0.01 GPa ps À1 /K to determine whether pressure itself is sufficient for reorientation.…”

Electrodynamics—molecular dynamics simulations of the stability of Cu nanotips under high electric field

“…The thickness of the Cu nanowire has a strong influence on the critical temperature of spontaneous reorientation [14], [15], [19] increasing the thickness from 1.76 nm to 3.39 nm changes the critical temperature from ~100 K to close to the melting point [15]. Although the lattice reorientation process has been directly observed in experiments where Au nanowires were stretched [20], pseudoelasticity and shape memory effect in Cu nanowires remain experimentally unverified [21].…”