The Fabrication Of The Magnetic Film Arrays And Its Magneto-optical Effects

Multi-functional magnetic material has been regarded as the key material of data storage and manipulation.It is a basic material for the highly sensitive sensors and measurements and has potential applications for magneto-optical storage,sensors with high density,non-reciprocal devices,laser gyroscope,telecommunication,solar energy,spin electric devices(spin hall and inverse spin hall effect),cloaking maternal with wide wavelength and multi-mode bio-molecular probe as well.It is difficult to get further enhanced magneto-optical effects,linear and nonlinear optical properties,spin and inverse spin hall effects only by using bulk magnetic maternals or single magnetic film.However,in recent years,researchers have paid attention to periodic arrays such as holes,bars,disks as well as particles and thin films consisting of ferromagnetic/noble metals and semi-conductive materials.In these system,a single resonant mode or multiple resonant modes can be realized by changing their structural parameters(hole size,disk radius,period,film thickness and composition),so as to realize the enhancement of the magneto-optical signal under the external magnetic field.Various materials,sizes and structures have been considered to design the nanostructures to get optimized magneto-optic and optical properties.However,how to get controlled nanostructures with large scale and to reveal the physical mechanism between the structures and the magnetic,linear or nonlinear optical,spin hall or reverse spin hall effect are still a challenging task.The main methods,process and results are as follows:1.The noble metal silver and the semi-conductive material ITO were introduced to keep the energy in the system to enhance the magneto-optical Kerr effects.The rotation is 2.34 times higher than that of the pure CoFeB thin film.2.A unique,large scaled,visual and controlled nanoporous magnetic film and silver nanopore were patterned by the anodic aluminum oxide(AAO)template supported on the aluminum(AAO/Al).Results suggest that the Ag nanoporous structure exhibits strong two-photon fluorescence effect whose intensity is 308 times higher than that of the pure Ag film.3.The magneto-optical Kerr signal of the AAO/Al-based CoFeB nanostructure arrays were found to be very different from those of the Al-based CoFeB granular film and a distinct resonance would appear as long as the AAO/Al substrate was introduced.Also,the blue-shift of the peak was obvious with the increase of the pore diameter of the AAO/Al substrate and Kerr oscillation was realized by extending the pore length.4.A critical thickness(51 nm-55 nm)of CoFeB films fabricated on AAO/Al substrate was found to realize the inversion of Kerr hysteresis,which promises a new pave to design magneto-optical arrays to realize the inversion of the magneto-optical Kerr signal.5.The second inversion of the Kerr hysteresis and tunable Kerr rotaion were obtained by changing the thickness of W in W/CoFeB/W/AAO/Al system.6.The shift of the transverse Kerr resonance position of the Py/AAO/Al was widely controlled by the pore size of the AAO membrane and the introduction of the Ta realized the transverse Kerr signal enhancement by more than 73 times when the Ta thickness was chosen to be 6 nm.