Tailoring the structural and magnetic properties of masked CoPt thin films using ion implantation

Durgesh Kumar,K Asokan,Tianli Jin,Surbhi Gupta,S N Piramanayagam,R Nongjai

doi:10.1063/1.5007767

Abstract

The effects of ion implantations through a mask on the structural and magnetic properties of Co80Pt20 films were investigated. The mask was patterned using the self-assembly of diblock copolymers. For implantation, high (40 keV for 14N+ and 100 keV for 40Ar+) and low (7.5 keV for 14N+ and 4.5 keV for 40Ar+) energy 14N+ and 40Ar+ ions were used to modify the structural and magnetic properties of these films. X-ray diffraction and TRIM simulations were performed for understanding the structural changes due to ion implantations. These results revealed the intermixing of Co atoms in lower layers and lattice expansion in Co80Pt20 magnetic and Ru layers. A lateral straggling of Co caused an increase in the exchange coupling in the masked region. Depletion of Co atoms in Co80Pt20 layer caused a decrease in the anisotropy constant, which were further confirmed by the alternating gradient force magnetometer and magnetic force microscopy results. The magnetic force microscopy images showed an increase in domain width and domain wall width confirming the above-mentioned effects.

Highlights

Patterning of magnetic thin films is important for their potential applications in the hard disk drive industry, in particular, in heated-dot magnetic recording.[1,2] One method to achieve patterning is to carry out ion-implantation in these magnetic materials through a mask.[3]
Implantation of low energy 14N+ ions clearly induce the shift of both Ru (002) and Co (002) peaks towards the lower 2θ values
We have studied the effects of high and low energy 14N+ and 40Ar+ ion implantations on the masked CoPt films

Summary

Introduction

Patterning of magnetic thin films is important for their potential applications in the hard disk drive industry, in particular, in heated-dot magnetic recording.[1,2] One method to achieve patterning is to carry out ion-implantation in these magnetic materials through a mask.[3]. The ability of block copolymers to self-assemble into nanometre sized regular and periodic arrays have attracted the attention of the researchers due to their ease of use.[6] the smallest feature size obtained using self-assembly of di-block copolymers is 3 nm,[7,8] which is good enough for heated-dot magnetic recording at 10 Tbpsi.[2,9,10] we have been investigating the effect of low and high energetic 14N+ and 40Ar+ ion-implantations on

Objectives

Results

Conclusion