Title: Complex Pattern Formation from Current-Driven Dynamics of Single-Layer Homoepitaxial Islands on Crystalline Conducting Substrates

Abstract

In this work, we report a systematic study of complex pattern formation resulting from the driven dynamics of single-layer homoepitaxial islands on surfaces of face-centered-cubic (fcc) crystalline conducting substrates under the action of an externally applied electric field. The analysis is based on an experimentally validated nonlinear model of mass transport via island edge atomic diffusion, which also accounts for edge diffusional anisotropy. We analyze the morphological stability and simulate the field-driven evolution of rounded islands for an electric field oriented along the fast edge diffusion direction. For larger-than-critical island sizes on {110} and {100} fcc substrates, we show that multiple necking instabilities generate complex island patterns, including not-simply-connected void-containing islands mediated by sequences of breakup and coalescence events and distributed symmetrically with respect to the electric field direction. We analyze the dependence of the formed patterns on the original island size and on the duration of application of the external field. Starting from a single large rounded island, we characterize the evolution of the number of daughter islands and their average size and uniformity. The evolution of the average island size follows a universal power-law scaling relation, and the evolution of the total edge length of the islands inmore » the complex pattern follows Kolmogorov-Johnson-Mehl-Avrami kinetics. Our study makes a strong case for the use of electric fields, as precisely controlled macroscopic forcing, toward surface patterning involving complex nanoscale features.« less

Authors:

Kumar, Ashish ^[1]; Dasgupta, Dwaipayan ^[1]; Maroudas, Dimitrios ^[1]

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+ Show Author Affiliations

1. Univ. of Massachusetts, Amherst, MA (United States)

Publication Date:

Thu Jul 27 00:00:00 EDT 2017

Research Org.:

Univ. of Massachusetts, Amherst, MA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1535765

Alternate Identifier(s):

OSTI ID: 1373131

Grant/Contract Number:  

FG02-07ER46407

Resource Type:

Accepted Manuscript

Journal Name:

Physical Review Applied

Additional Journal Information:

Journal Volume: 8; Journal Issue: 1; Journal ID: ISSN 2331-7019

Publisher:

American Physical Society (APS)

Country of Publication:

United States

Language:

English

Subject:

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; growth; thin films; pattern formation