| 研究実績の概要 |
In the past fiscal year, more fabrication and measurements of antiferromagnetic-FeRh-based magnetic tunnel junctions were performed and the bipolar tunneling magnetoresistance was confirmed. The first principles calculations on the tunneling magnetoresistance effect in the FeRh/MgO/Fe stacks have been carried out. New antiferromagnetic materials, including IrMn-based noncollinear antiferromagnetic stacks, Cr/Fe-based synthetic antiferromagnetic structures, and RuO2 collinear antiferromagnetic films were also prepared. The deposition conditions of these antiferromagnetic thin films were optimized by characterizing the surface morphology and structures of these samples by atomic force microscope and X-ray diffraction. The best condition was achieved for high-quality antiferromagnetic films.
|
| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
We performed characterizations and optimizations for the antiferromagnetic (AFM) materials, as well as designed/engineered new AFM materials and related structures, which follows our research plans. Therefore, the project is progressing rather smoothly.
|
| 今後の研究の推進方策 |
In the coming fiscal year, I will fabricate tunnel junction devices based on the optimized antiferromagnetic thin films. For examples, I plan to fabricate antiferromagnetic tunnel junctions with the following stacks, (1) Al2O3(0001)-substrate//Ru/Cu/NiFe/IrMn/MgO/Ru or CoFe/Cap, (2) TiO-substrate//RuO2/TiO/RuO2 or CoFe/Cap, (3) Al2O3(0001)-substrate//Ru/Cu/NiFe/PtMn/MgO/PtMn/Cap. The stacks of antiferromagnetic tunnel junctions will be patterned into nano- and micro-sized pillars by microfabrication techniques, including EB and UV lithography, Ar ion milling and lift off technique. Transport measurements, such as the magnetic field and voltage dependences of tunneling resistance, tunneling conductance, and magnetoresistance, will be carried out at room temperature and low temperatures.
|
