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▲ [9p-PB1-17] Annealing effects of exchange bias properties for Co-Mn/Ir-Mn bilayers
Keywords:Exchange bias
Co-Mn binary alloys are stable to be the fcc phase in the Co-rich composition for the bulk experiments [1]. In the case of films, bcc Co-Mn films were successfully grown on optimum substrates such as GaAs and MgO in the Co-rich composition [2, 3]. The fcc Co-Mn shows antiferromagnetic behavior, on the other hand, the bcc Co-Mn shows ferromagnetic behavior. The systematical investigation of the bcc Co-Mn is still lacking. In this study, the exchange bias properties of bcc Co-Mn and IrMn were investigated.
Samples were prepared by the ultra high vacuum magnetron sputtering. The stacking structures were MgO(100) sub./ Co-Mn (3)/ IrMn (10)/ Ru (3) (thickness is in nm). All layers were deposited at the room temperature (RT) and the in-situ post annealing temperature (Ta) for the Co-Mn layer was changed from RT to 500ºC. Ex-situ annealing was done after the deposition of Ru capping layer in a magnetic field of 5 kOe. The nominal film composition of Co-Mn was Co75Mn25 (at.%). The crystalline structures were characterized by x-ray diffraction (XRD). The magnetic properties were measured by a vibrating sample magnetometer (VSM).
Saturation magnetization was 950 emu/cm3 at RT, which was smaller than the reported value [3]. The exchange bias shift of 490 Oe was observed for the annealed sample. Further annealing temperature dependence of the exchange bias will be presented.
[1] K. Ishida, T. Nishizawa, Bull. Alloy. Phase Diagrams 11 125 (1990).
[2] D. Wu et al., Phys. Rev. B 63 214403 (2001).
[3] R. J. Snow et al., J. Magn. Magn. Mater. 419, 490 (2016)
Samples were prepared by the ultra high vacuum magnetron sputtering. The stacking structures were MgO(100) sub./ Co-Mn (3)/ IrMn (10)/ Ru (3) (thickness is in nm). All layers were deposited at the room temperature (RT) and the in-situ post annealing temperature (Ta) for the Co-Mn layer was changed from RT to 500ºC. Ex-situ annealing was done after the deposition of Ru capping layer in a magnetic field of 5 kOe. The nominal film composition of Co-Mn was Co75Mn25 (at.%). The crystalline structures were characterized by x-ray diffraction (XRD). The magnetic properties were measured by a vibrating sample magnetometer (VSM).
Saturation magnetization was 950 emu/cm3 at RT, which was smaller than the reported value [3]. The exchange bias shift of 490 Oe was observed for the annealed sample. Further annealing temperature dependence of the exchange bias will be presented.
[1] K. Ishida, T. Nishizawa, Bull. Alloy. Phase Diagrams 11 125 (1990).
[2] D. Wu et al., Phys. Rev. B 63 214403 (2001).
[3] R. J. Snow et al., J. Magn. Magn. Mater. 419, 490 (2016)