R&D: Correlation of Magnetic and MR Properties of Nanoporous Co/Pd Thin Multilayers Fabricated on Anodized TiO2 Templates

Nature Scientific Reports has publishedan article written by Thi Ngoc Anh Nguyen, Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam, and Vietnam Academy of Science and Technology, Graduate University of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam, Julia Kasiuk, Wen-Bin Wu, Julia Fedotova, Institute for Nuclear Problems, Belarusian State University, 220006, Minsk, Belarus, Janusz Przewoźnik, Czesław Kapusta, Department of Solid State Physics, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, 30-059, Krakow, Poland, Olga Kupreeva, Serguei Lazarouk, Belarusian State University of Informatics and Radioelectronics, 220013, Minsk, Belarus Thi Thanh Hai Cao, Physics Department, Hanoi National University of Education, 144 Xuan Thuy, Cau Giay, Hanoi, Vietnam, Thi Thanh Thuy Nguyen, Physics Department, Hanoi National University of Education, 144 Xuan Thuy, Cau Giay, Hanoi, Vietnam , Hung Manh Dinh, Physics Department, Hanoi National University of Education, 144 Xuan Thuy, Cau Giay, Hanoi, Vietnam, Khanh Tung Do, Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam, Thanh Huong Nguyen, Hong Ky Vu, Dinh Lam Vu, Institute of Materials Science, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam, and Vietnam Academy of Science and Technology, Graduate University of Science and Technology, 18 Hoang Quoc Viet, Cau Giay, Hanoi, Vietnam, and Johan Åkerman, Department of Physics, University of Gothenburg, 41296, Gothenburg, Sweden.

Abstract: “In this study, we consider a technological approach to obtain a high perpendicular magnetic anisotropy of the Co/Pd multilayers deposited on nanoporous TiO₂ templates of different types of surface morphology. It is found that the use of templates with homogeneous and smoothed surface relief, formed on silicon wafers, ensures conservation of perpendicular anisotropy of the deposited films inherent in the continuous multilayers. Also, their magnetic hardening with doubling of the coercive field is observed. However, inhomogeneous magnetic ordering is revealed in the porous films due to the occurrence of magnetically soft regions near the pore edges and/or inside the pores. Modeling of the field dependences of magnetization and electrical resistance indicates that coherent rotation is the dominant mechanism of magnetization reversal in the porous system instead of the domain-wall motion typical of the continuous multilayers, while their magnetoresistance is determined by electron-magnon scattering, similarly to the continuous counterpart. The preservation of spin waves in the porous films indicates a high uniformity of the magnetic ordering in the fabricated porous systems due to a sufficiently regular pores array introduced into the films, despite the existence of soft-magnetic regions. The results are promising for the design and fabrication of future spintronic devices.“