Room Temperature Magnetic Memory Effect in Cluster-Glassy Fe-doped NiO Nanoparticles.

Ashish Chhaganlal Gandhi,B Vijaya Kumar,Sheng Yun Wu,P Muralidhar Reddy,Jen-Chih Peng,Chun-Ming Wu,Tai-Yue Li

doi:10.3390/nano10071318

Abstract

The Fe-doped NiO nanoparticles that were synthesized using a co-precipitation method are characterized by enhanced room-temperature ferromagnetic property evident from magnetic measurements. Neutron powder diffraction experiments suggested an increment of the magnetic moment of 3d ions in the nanoparticles as a function of Fe-concentration. The temperature, time, and field-dependent magnetization measurements show that the effect of Fe-doping in NiO has enhanced the intraparticle interactions due to formed defect clusters. The intraparticle interactions are proposed to bring additional magnetic anisotropy energy barriers that affect the overall magnetic moment relaxation process and emerging as room temperature magnetic memory. The outcome of this study is attractive for the future development of the room temperature ferromagnetic oxide system to facilitate the integration of spintronic devices and understanding of their fundamental physics.

Highlights

The antiferromagnetic (AF) metal oxide nanoparticles (NPs) have attracted enormous attention because of their promising technological applications and fundamental physics
The further development in functionalized nickel oxide (NiO) nanostructure is focused on obtaining a room temperature (RT) ferromagnetism without comprising the structure in order to facilitate the possible integration of spintronic devices
RT ferromagnetism in NiO NPs can be achieved through transition metal (TM)-doping, for example, Fe, which opens up their potential applications in the future advanced spintronic devices [13,14,15]

Summary

Introduction

The antiferromagnetic (AF) metal oxide nanoparticles (NPs) have attracted enormous attention because of their promising technological applications and fundamental physics. RT ferromagnetism in NiO NPs can be achieved through transition metal (TM)-doping, for example, Fe (either due to substitution or the formed defect clusters), which opens up their potential applications in the future advanced spintronic devices [13,14,15]. The properties of such a system can be tailored by controlling both the particle size and Fe-dopant concentration, which results in a complex magnetic property [16,17,18,19,20,21,22]. Our findings suggest that the RT magnetic memory effect in Fe-doped NiO NPs is mediated through intrinsic intraparticle interactions

Materials and Methods

Findings

Temperature Dependence of Magnetization