Role of TbFe on Perpendicular Magnetic Anisotropy and Giant Magnetoresistance Effect in [Co/Ni]_N-Based Spin Valves

The exchange-coupled [Co/Ni]N/Tb Fe nano-magnetic films can display strong perpendicular magnetic anisotropy(PMA) which depends on the Tb:Fe component ratio, Tb Fe layer thickness and the repetition number N of [Co/Ni]Nmultilayer. Perpendicular spin valves in the nano thickness scale, consisting of a [Co/Ni]3free and a [Co/Ni]5/Tb Fe reference multilayer, show high giant magnetoresistance(GMR) signal of 6.5 % and a large switching field difference over3 k Oe. However, unexpected slanting of the free layer magnetization, accompanied by a reduced GMR ratio, was found to be caused by the presence of a thick Fe-rich or even a thin but Tb-rich Tb Fe layer. We attribute this phenomenon to the large magnetostriction effect of Tb Fe which probably induces strong stress acting on the free layer and hence reduces its interfacial PMA.

Providing insight into exchange coupling within nanomagnetism:mechanism,micromagnetic simulation,synthesis and biomedical application

Exchange coupling within nanomagnetism is a rapidly evolving field with significant implications for that plays a crucial role in the development of magnetic nanomaterials.Manipulating exchange coupling interaction enables the magnetic systems to overcome limitations associated with size-dependent magnetic behavior within nano scale,thereby improving their magnetic properties and providing for superior performance in biomedical applications compared with single-phase magnetic materials.Understanding the underlying mechanism of exchange coupling and its impact on macroscopic magnetic properties is crucial for the design and application of such magnetic materials.This review provides an overview of recent advances in interfacial exchange coupling among different magnetic modalities-ferromagnetism,ferrimagnetism,and antiferromagnetism-based on core-shell magnetic nanoparticles(MNPs).Additionally,this review discusses micromagnetic simulations to gain insights into the relationship between the microscopic magnetic structure(size,shape,composition,and exchange coupling)and the resulting macroscopic properties.The controlled synthesis of MNPs is summarized,including one-step method and two-step method.The precise manipulation of interfacial characteristics is of great importance,albeit challenging,as it allows for the finetuning of magnetic properties tailored for specific applications.The review also explores potential applications of coreshell MNPs in magnetic resonance imaging,hyperthermia therapy,targeted drug delivery,and advanced neuromodulation.

Entropy Generation Analysis in Convective Ferromagnetic Nano Blood Flow Through a Composite Stenosed Arteries with Permeable Wall

The study of heat transfer is of significant importance in many biological and biomedical industry problems.This investigation comprises of the study of entropy generation analysis of the blood flow in the arteries with permeable walls. The convection through the flow is studied with compliments to the entropy generation. Governing problem is formulized and solved for low Reynold's number and long wavelength approximations. Exact analytical solutions have been obtained and are analyzed graphically. It is seen that temperature for pure water is lower as compared to the copper water. It gains magnitude with an increase in the slip parameter.