Research Projects

The present proposal intends to study the magnetization dynamics in nonmagnet (NM)/ferromagnet (FM) interfaces in the field of organic spintronics. The advancement of spintronics has sparked significant research interest, where spin degrees of freedom of electrons are exploited for information storage, transmission, and processing. However, next-generation spintronics may hold great promise due to the presence of an essential ingredient - pure spin current. The supremacy of the pure spin current-based gadgets is the flow of spin angular momentum, which reduces the joule heating effect and can lead to faster operation. However, efficient generation and transmission of pure spin currents offer great challenges. Pure spin current can be generated by the spin pumping (SP) method, occurring by the interplay of the FM and NM material. In an NM/FM heterostructure, external perturbation causes magnetization precession in the FM layer, which leads to the transport of spin angular momentum to the NM layer. The productivity of the SP in the NM/FM bilayer firmly depends on the spin-orbit coupling (SOC) of the NM layer as well as the quality of the interface. Although some inorganic materials are widely used for spin pumping studies, due to the strong SOC, spin relaxation time and spin diffusion length (SDL) are very small. On the other hand, polymers (consist of light elements like C and H) may able to exhibit weak SOC such that spin orientation can be preserved for a relatively long time and spin information can be transferred over longer distances. Over the past decades, the research on organic spintronics has been booming, and lots of efforts have been made for the development of this field. Plastic spintronics (a subfield of organic spintronics) became an emerging field of research that coalesces spintronics with polymers. In this field, the utilization of polymers includes its rich physics, flexible chemistry, and cost efficiency. Among them, conjugated polymers may prove beneficial because they consist of a backbone of alternating single and double bonds, responsible for the creation of a delocalized π-electron system (favorable for creating spin-polarized currents in spintronic devices). Here, we propose to study the magnetization dynamics of the heterostructure polymer/FM. The magnetic material present in an external magnetic field experiences a torque that leads to a precessional motion about the direction of the applied field. However, to minimize the Zeeman energy, the magnetic moments tend to orient along the field direction. As a result, they follow a damped spiral motion around the field direction, known as precessional magnetization dynamics. Landau-Lifshitz-Gilbert equation is used to analyze the magnetization dynamics. Here, the magnetization dynamics of the polymer/FM heterostructure will be investigated by a custom-built Time-resolved magneto-optical Kerr effect (TR-MOKE) microscope based on a two-color collinear pump-probe arrangement.