| Project Detail |
Novel and compaImplementation of solid-state magnetic field sensors with ultra-high sensitivity and ultra-low magnetic-field detectivity is mandatory to accelerate the development of individualized and precision healthcare devices and promote the change to more energy efficient green technologies. Unlike other studies, the project will provide major advances in the field of spintronic tunneling magnetoresistance (TMR) sensors by pushing their limit of detectivity to the femtoTesla range without using external tools as magnetic flux concentrator, which is an artificial technique to increase sensitivity regardless to the origin of limitation in TMR multilayer structure as noise sources. For that, FEMTOSense is to pinpoint the origin and mechanisms that govern all noise contributions, and their control, on-demand, using materials science and device engineering. To do this, I will develop highly (001)-textured spinel oxide MgAl2O4 (MAO) tunneling barriers enabling tunable lattice matching with wide range of ferromagnetic electrodes particularly CoFeB, to suppress the interfacial imperfection (noise) at the interface and improve TMR ratio. I will also improve the quality of the ferromagnetic electrodes by development of functional sensing layers consisting of sandwich-like amorphous ferromagnet. The ferromagnetic sandwich comprises thin layers of super-soft NiFe inserted between amorphous phase of CoFeBTa ferromagnetic layers. The former is to prevent propagation of 111-texture of NiFe to MAO barrier, ensuring ordering interface with minimized electronic noises. The latter is to tune the structural and magnetic characteristics of the sensing layers, enabling high sensitivity and suppressing magnetic noise at the sensing layer. Finally, I will establish a framework to map all sources of noise within each of the spintronic sensor building blocks, and identify the method of treatment by theoretical modeling for demonstration of femtoTesla tunneling magnetoresistnce sensors. |
