Interface-Induced Ferromagnetism in lateral NiBr2 and NiCl2 Heterostructure

TL;DR

This study uses ab initio simulations and Monte Carlo methods to explore interface-induced ferromagnetism and skyrmion phases in lateral NiBr2/NiCl2 heterostructures, revealing multiple phase transitions and potential for magnetic control.

Contribution

It introduces a novel approach combining ab initio calculations and Monte Carlo simulations to analyze skyrmion phases and interface-induced ferromagnetism in NiBr2/NiCl2 heterostructures.

Findings

Identified three distinct magnetic phase transitions at different temperatures.

Discovered interface-induced ferromagnetism in the heterostructure.

Mapped skyrmion phase stability in the heterostructure system.

Abstract

Magnetic skyrmions are promising candidates for future information storing and processing devices. There are different routes for stabilizing the skyrmions. Understanding the interplay mechanism between different scenarios of skyrmion formation is one key factor that can reveal new paths for controlling skyrmion phases. Inspired by the flexibility of two-dimensional materials that offer an exciting playground for manipulating spin textures, we conducted \textit{ab initio} simulations and utilized four-state spin framework to determine magnetic parameters of lateral heterostructure formed by NiBr2 and NiCl2 Monolayers. The obtained spin interaction parameters are utilized to determine the skyrmionic phases via Monte Carlo simulation. Monte Carlo simulation results suggest three distinct phase transition mechanisms exist in the present system. Namely, examination of heat capacity versus temperature curve obtained from average anisotropic exchange energy yields a phase transition between paramagnetic and spin-spiral states at $5$K for pristine NiBr2, a paramagnetic-mixed skyrmion state transition occurs at 17 K for pristine NiCl2, and a high-temperature ferromagnetic-paramagnetic transition at T=80 K is observed for the heterostructure region, indicating that some kind of intrinsic ferromagnetism may originate at the interface of pristine Janus structures.