# Consequences of lattice mismatch for phase equilibrium in heterostructured solids

## TL;DR

This paper investigates how lattice mismatch influences phase equilibrium in heterostructured solids, revealing complex phase behaviors and coexistence scenarios through theoretical modeling and simulations.

## Contribution

It introduces a mean field theoretical approach combined with an adapted Maxwell construction to analyze elastic phase separation in lattice-mismatched solids.

## Key findings

- Identification of uniform and modulated phases across temperature and composition ranges.
- Unconventional coexistence scenarios due to mechanical costs.
- Agreement between mean field theory predictions and Monte Carlo simulations.

## Abstract

Lattice mismatch can substantially impact the spatial organization of heterogeneous materials. We examine a simple model for lattice-mismatched solids over a broad range of temperature and composition, revealing both uniform and spatially modulated phases. Scenarios for coexistence among them are unconventional due to the extensive mechanical cost of segregation. Together with an adapted Maxwell construction for elastic phase separation, mean field theory predicts a phase diagram that captures key low-temperature features of Monte Carlo simulations.