Influence of surface energy anisotropy on nucleation and crystallographic texture of polycrystalline deposits

TL;DR

This study investigates how interface energy anisotropy influences nucleation and texture development in polycrystalline films, revealing its significant impact on nucleation rates and microstructure evolution through theoretical and simulation approaches.

Contribution

The paper introduces novel solutions to the Winterbottom construction for strong anisotropy and develops a 2D Monte Carlo model to simulate anisotropic polycrystalline growth.

Findings

Stronger anisotropy reduces nucleation dependence on driving force.

Initial texture significantly influences nucleation probability.

Anisotropic nucleation can accelerate or delay texture evolution.

Abstract

This paper aims to elucidate the role of interface energy anisotropy in orientation selection during nucleation of new grains in a polycrystalline film growth. An assessment of (heterogeneous) nucleation probability as function of orientation of both the bottom grain and of the nucleus was developed (using the concepts of classical nucleation theory). Novel solutions to the generalized Winterbottom construction were described in cases of very strong anisotropy and arbitrary orientations. In order to demonstrate the effect on the film crystallographic texture, a 2D Monte Carlo algorithm for anisotropic polycrystalline growth was used to simulate growth of films with columnar microstructure. The effect of strength of anisotropy, the deposition rate and initial texture were investigated. Results showed that with larger strength of anisotropy, the nucleation rate is less dependent on the driving force, but more dependent on the initial texture. With certain initial textures, the anisotropic nucleation may even be either impossible or having probability close to one irrespective of the driving force. Depending on the conditions, the anisotropic nucleation could hasten the evolution towards the interface-energy minimizing texture or retard it. Based on these insights, a hypothesis was offered to explain a peculiar texture evolution in electrodeposited nickel.