Fabrication of Flexible Oriented Magnetic Thin Films with Large in-plane Uniaxial Anisotropy by Roll-to-roll Nanoimprint Lithography

TL;DR

This paper demonstrates wafer-scale fabrication of flexible Fe nanostripe magnetic thin films with large in-plane uniaxial anisotropy using roll-to-roll nanoimprint lithography, achieving high energy product and specific magnetic properties.

Contribution

It introduces a novel roll-to-roll nanoimprint process for creating dense, flexible Fe nanostripe magnetic films with significant uniaxial anisotropy and high magnetic energy product.

Findings

Large in-plane uniaxial anisotropy observed

Energy product (BH)max exceeds 3 MGOe at room temperature

Magnetization reversal driven by non-coherent rotation processes

Abstract

Here, we report wafer scale fabrication of densely packed Fe nanostripe-based magnetic thin films on a flexible substrate and their magnetic anisotropy properties. We find that Fe nanostripes exhibit large in-plane uniaxial anisotropy and nearly square hysteresis loops with energy products (BH)max exceeding 3 MGOe at room temperature. High density Fe nanostripes were fabricated on 70 nm flexible polyethylene terephthalate (PET) gratings, which were made by roll-to-roll (R2R) UV nanoimprintlithography technique. Observed large in-plane uniaxial anisotropies along the long dimension of nanostripes are attributed to the shape. Temperature dependent hysteresis measurements confirm that the magnetization reversal is driven by non-coherent rotation reversal processes.