Magnetization Switching in the GdFeCo Films with In-Plane Anisotropy via Femtosecond Laser Pulses

Ferrimagnetic rare-earth substituted metal alloys GdFeCo were shown to exhibit the phenomenon of all-optical magnetization switching via femtosecond laser pulses. All-optical magnetization switching has been comprehensively investigated in out-of-plane magnetized GdFeCo films; however, the films with the in-plane magnetic anisotropy have not yet been studied in detail. We report experimental observations of the magnetization switching of in-plane magnetized GdFeCo films by means of the femtosecond laser pulses in the presence of a small magnetic field of about 40 µT. The switching effect has a threshold both in the applied magnetic field and in the light intensity

Magneto-optical plasmonic heterostructure with ultranarrow resonance for sensing applications

Currently, sensors invade into our everyday life to bring higher life standards, excellent medical diagnostic and efficient security. Plasmonic biosensors demonstrate an outstanding performance ranking themselves among best candidates for different applications. However, their sensitivity is still limited that prevents further expansion. Here we present a novel concept of magnetoplasmonic sensor with ultranarrow resonances and high sensitivity. Our approach is based on the combination of a specially designed one-dimensional photonic crystal and a ferromagnetic layer to realize ultralong-range propagating magnetoplasmons and to detect alteration of the environment refractive index via observation of the modifications in the Transversal Magnetooptical Kerr Effect spectrum. The fabrication of such a structure is relatively easy in comparison with e.g. nanopatterned samples. The fabricated heterostructure shows extremely sharp (angular width of 0.06 degrees) surface plasmon resonance and even sharper magnetoplasmonic resonance (angular width is 0.02 degrees). It corresponds to the propagation length as large as 106 mu m which is record for magnetoplasmons and promising for magneto-optical interferometry and plasmonic circuitry as well as magnetic field sensing. The magnitude of the Kerr effect of 11% is achieved which allows for detection limit of 1.10(-6). The prospects of further increase of the sensitivity of this approach are discussed

Magnetic nanoribbons with embedded cobalt grown inside single-walled carbon nanotubes

Molecular magnetism and specifically magnetic molecules have recently gained plenty of attention as key elements for quantum technologies, information processing, and spintronics. Transition to the nanoscale and implementation of ordered structures with defined parameters is crucial for advanced applications. Single-walled carbon nanotubes (SWCNTs) provide natural one-dimensional confinement that can be implemented for encapsulation, nanosynthesis, and polymerization of molecules into nanoribbons. Recently, the formation of atomically precise graphene nanoribbons inside SWCNTs has been reported. However, there have been only a limited amount of approaches to form ordered magnetic structures inside the nanotube channels and the creation of magnetic nanoribbons is still lacking. In this work we synthesize and reveal the properties of cobalt-phthalocyanine based nanoribbons (CoPcNRs) encapsulated in SWCNTs. Raman spectroscopy, transmission electron microscopy, absorption spectroscopy, and density functional theory calculations allowed us to confirm the encapsulation and to reveal the specific fingerprints of CoPcNRs. The magnetic properties were studied by transverse magnetooptical Kerr effect measurements, which indicated a strong difference in comparison with the pristine unfilled SWCNTs due to the impact of Co incorporated atoms. We anticipate that this approach of polymerization of encapsulated magnetic molecules inside SWCNTs will result in a diverse class of protected low-dimensional ordered magnetic materials for various applications