Magnetic Domain Wall Engineering in a Nanoscale Permalloy Junction

TL;DR

This study uses micromagnetic simulations to analyze how the magnetic domain structures and switching behaviors in nanoscale Permalloy junctions depend on thickness, informing the design of stable MRAM devices.

Contribution

It reveals the formation of specific domain walls and the thickness-dependent magnetic switching fields in nanoscale Permalloy junctions, advancing magnetic memory technology.

Findings

Formation of 90-degree and 45-degree domain walls depending on thickness

Magnetic switching fields vary with thickness, peaking between 7 nm and 22 nm

Large switching fields enhance MRAM stability

Abstract

Nanoscale magnetic junction provides a useful approach to act as the building block for magnetoresistive random access memories (MRAM), where one of the key issues is to control the magnetic domain configuration. Here, we study the domain structure and the magnetic switching in the Permalloy (Fe20Ni80) nanoscale magnetic junctions with different thicknesses by using micromagnetic simulations. It is found that both the 90-degree and 45-degree domain walls can be formed between the junctions and the wire arms depending on the thickness of the device. The magnetic switching fields show distinct thickness dependencies with a broad peak varying from 7 nm to 22 nm depending on the junction sizes, and the large magnetic switching fields favor the stability of the MRAM operation.