arXiv subjects

Vivek K. Malik

Publications and source records attributed to Vivek K. Malik.

3 recordsLinked to original sources

arXiv2026

Influence of oxygen ion implantation on magnetic microstructure in Pt/Co/Pt multilayers with perpendicular magnetic anisotropy

The interaction of oxygen with cobalt and cobalt-based alloys has been a very important topic in the field of spintronics as it leads to enhanced orbital anisotropy and interfacial Dzyaloshinskii-Moriya interaction (DMI), which are crucial in the context of applications such as magnetic tunnel junctions (MTJs) based data storage and domain wall (DW) motion. To understand the complex and interesting relationship between oxygen and ferromagnetic (FM)/heavy metal (HM) interfaces, we studied controlled oxygen ion implantation in a cobalt layer located in a Pt/Co 1.2 /Pt (nm) multilayer with a specific structure. At high implantation fluence, the perpendicular anisotropy was lost, as verified by in-plane hysteresis measurements. Under low magnetic field conditions, the DW dynamics of Co/Pt multilayers were analyzed, highlighting key parameters such as DW velocity, roughness amplitude, and roughness exponent. After O+-ion implantation, the DW velocity increased by more than 50 times, rising from 5 um/s to 300 um/s compared with the as-deposited multilayer. The fundamental cause of this improvement is the structural and magnetic changes brought by the implantation, which successfully lower the energy barriers preventing DW movements. The results show how oxygen implantation can be used to precisely tailor the ferromagnetic interfaces, leading to promised improvements in the functionality of next-generation spintronic devices.

cond-mat.mtrl-sci↗

arXiv2025

Engineered Inclined Energy Landscapes Enabling Free Flow of Magnetic Microstructures for Artificial Neuron Applications

Spintronic-based brain-inspired neuromorphic computing has recently attracted significant attention due to the exceptional properties of magnetic microstructures, including nanoscale dimensions, high stability, and low energy consumption. Despite these advantages, the practical integration of such microstructures into functional devices remains challenging. Fabrication processes are often complex and prone to stochastic effects, such as unwanted pinning and thermal-induced instabilities, which limit device reliability and scalability. Addressing these challenges is crucial for advancing spintronic neuromorphic architectures toward real-world applications. Thus, to reduce these effects we have proposed a design which is experimentally feasible and require less energy as compared to existing one. By engineering the system anisotropy into a sawtooth-type energy landscape, we have achieved free flow of these microstructures and successfully emulated integrate and fire (IF) function of biological neuron. Thus, proposed design presents an experimentally reliable and energy efficient external stimuli approach for tailoring magnetic microstructures dynamic behaviours, resulting in low energy consumption of 23.66 fJ per spike paving the way for the development of skyrmion-based futuristic neuromorphic computing device applications.

physics.comp-ph↗

arXiv2015

Controlling the switching field in nanomagnets by means of domain-engineered antiferromagnets

Using soft x-ray spectromicroscopy, we investigate the magnetic domain structure in embedded nanomagnets defined in La$_{0.7}$Sr$_{0.3}$MnO$_3$ thin films and LaFeO$_3$/La$_{0.7}$Sr$_{0.3}$MnO$_3$ bilayers. We find that shape-controlled antiferromagnetic domain states give rise to a significant reduction of the switching field of the rectangular nanomagnets. This is discussed in the framework of competition between an intrinsic spin-flop coupling and shape anisotropy. The data demonstrates that shape effects in antiferromagnets may be used to control the magnetic properties in nanomagnets.

cond-mat.mtrl-sci↗