Study on physical mechanisms and technological conditions to fabricate nanoporous [Co/Pd]/AFM (AFM=FeMn, IrMn) multilayered films: i) having a high perpendicular magnetic anisotropy (PMA); ii) having a large perpendicular exchange bias field (HPEB) at room temperature; iii) being possible to modulate PMA and HPEB by changing the structural parameters of multilayers (e.g. antiferromagnetic materials, layer thicknesses, number of layers…) and the structural parameters of nanoporous templates (e.g. pore size, pore-to-pore distance, surface morphology...) towards next-generation Spintronics applications with more advanced features.

- The [Co/Pd]/AFM (AFM=FeMn, IrMn) multilayered films have been fabricated successfully on SiO2 flat substrates and Al2O3 and TiO2 nanoporous templated with pore dimensions of about 30 nm and 50 nm. The developed multilayers have been systematically investidated in order to optimize structural parameters, technological conditions and to understand the physical mechanism. The results show that the developed [Co/Pd]/AFM (AFM=FeMn, IrMn) nanoporous multilayered films have: i) a high perpendicular magnetic anisotropy (PMA); ii) a large perpendicular exchange bias field (HPEB) at room temperature; iii) a possibility to modulate PMA and HPEB by changing the structural parameters of multilayers (e.g. antiferromagnetic materials, layer thicknesses, number of layers…) and the structural parameters of nanoporous templates (e.g. pore size, pore-to-pore distance, surface morphology...). The results on spin valves based- [Co/Pd]/AFM (AFM=FeMn, IrMn) multilayers indicate that these materials are suitable for the future designing Spintronics nanodevices with high PMA and large HPEB by using a simple, inexpensive method without relying on expensive lithography equipment like a conventional semiconductor fabrication.

- The results were published in 02 ISI papers including 01 Q1 paper with IF=3,43, 01 Q2 paper with IF=2,37, and 01 article in national journals. The results also were presented at 02 international and 02 national conferences in which 02 presentations are invited talks. The project also helps to support 02 MSc students (successfully defended the theses in 2019 and 2020 with the score of 9,2 and 9,9 out of 10, respectively).  

- Following the success of this project, the two groups are continuing to expand our cooperation in research on development of novel nanomagnetic materials and structures for Spintronics and Biomedical Agriculture (BMA). Recently, a new joint project between 2 research groups has been funded by VAST under project number QTBY01.05/21-22. Another joint project within the framework of the bilateral cooperation on S&T between Vietnam and Belarus is going to be funded by the Ministry of Science and Technology.

- Reliazing of the nanoporous [Co/Pd]/AFM (AFM=FeMn, IrMn) multilayered films by using an inexpensive, reproducible nanoporous Al2O3 and TiO2 templates without relying on expensive traditional lithography methods (normally require complex, expensive equipment and time-consuming technological processes) is a new advanced research direction. This research project thus provides a new technology solution for nanomagnetic materials and structures fabrication in Vietnam. It leads to a new approach to studying and manufacturing magnetic nano materials and Spintronics devices not only in IMS, host Vietnamese institution but also in other research institutions in Vietnam in order to catch up with the world.

- These nanoporous films have strong perpendicular magnetic anisotropies (PMA) and high perpendicular exchange bias fields (HPEB) at room temperature. The PMA and HPEB in these nanoporous materials are easily controlled by controlling the structural parameters of multilayers (e.g. antiferromagnetic materials, layer thicknesses, number of layers…) and the structural parameters of nanoporous templates (e.g. pore size, pore-to-pore distance, surface morphology...). The results on spin valves based-[Co/Pd]/AFM material systems with PMA and PEB at room temperature shows that these material systems are suitable for applying in novel magnetic recording and Spintronics devices. The success of the topic will surely attract great attention of the scientific community and technology companies.

- The project is at the cutting edge of applied physics, nanomaterials and nanotechnology and will provide a solid foundation for the academic career of the PhD and Master students as well as the researchers. These projects have already led to important collaborations with Belarus and will continue to put Vietnamese research in nanomaterials and nanotechnology as well as applied physics on the international map. It is a likely new research field in Vietnam and will thus open up an entirely new research direction and inspire other research groups to follow suit.

- Scientific papers in referred journals (list):
1.    “Complex magnetic ordering in nanoporous [Co/Pd]5-IrMn multilayers with perpendicular magnetic anisotropy and its impact on magnetization reversal and magnetoresistance”, Wen-Bin Wu, Julia Kasiuk, Julia Fedotova, Thi Ngoc Anh Nguyen, Khanh Tung Do, Thanh Huong Nguyen, Hong Ky Vu, Dinh Lam Vu, Janusz Przewoźnik, Czesław Kapusta, Olga Kupreeva, Serguei Lazarouk, Johan Åkerman, Phys. Chem. Chem. Phys. 22, 3661, 2020
2.    “Influence of interfacial magnetic ordering and field-cooling effect on perpendicular exchange bias and magnetoresistance in nanoporous IrMn-[Co/Pd] films”, Wen-Bin Wu, Julia Kasiuk, Thi Ngoc Anh Nguyen, Janusz Przewoźnik, Julia Fedotova, Czesław Kapusta, Olga Kupreeva, Serguei Lazarouk, Khanh Tung Do, Thanh Huong Nguyen, Hong Ky Vu, Pham Hoai Linh, Dinh Lam Vu, Johan Åkerman, J. Appl. Phys. 127, 223904, 2020
3.    “Tăng cường trường trao đổi dịch theo phương vuông góc trong hệ vật liệu [Co/Pd]-IrMn với lớp xen giữa CoFe siêu mỏng”, Nguyễn Thị Thanh Thủy, Cao Thi Thanh Hải, Nguyễn Thị Huế, Đinh Hùng Mạnh, Vũ Hồng Kỳ, Đỗ Khánh Tùng, Nguyễn Thanh Hường, Nguyễn Thị Ngọc Anh, Tạp chí Khoa học và Công nghệ, Đại học Thái Nguyên, T. 225, S. 06, p. 498-504, 2020.

- Other products (if applicable): National and International Conferences
1.    “Sự phụ thuộc của lực kháng từ và trường trao đổi dịch theo phương vuông góc vào các thong số cấu trúc trong các màng mỏng đa lớp [Co/Pd]N/IrMn”, Nguyễn Thanh Hường, Phạm Hoài Linh, Nguyễn Thị Ngọc Anh, Hội nghị nữ khoa học và công nghệ vì sự phát triển bền vững toàn quốc lần thứ I, Oct. 16, 2019 (POSTER)
2.    “Tunability of out-of-plane exchange bias in [Co/Pd]-IrMn multilayers”, Nguyen Thi Hue, Cao Thi Thanh Hai, Nguyen Thi Thanh Thuy, Dinh Hung Manh, Do Khanh Tung, Nguyen Thanh Huong, Vu Dinh Lam, Nguyen Thi Ngoc Anh, the 4th International Conference on Advanced Materials and Nanotechnology (ICAMN 2019), Oct. 13-16, 2019 Hanoi, Vietnam (POSTER)
3.    “Nghiên cứu sự phụ thuộc của trường trao đổi dịch theo phương vuông góc vào các thông số cấu trúc trong màng đa lớp [Co/Pd]N/IrMn”, Cao Thị Thanh Hải, Nguyễn Thị Thanh Thủy, Nguyễn Thị Huế, Đinh Hùng Mạnh, Phạm Quang Ngân, Đỗ Khánh Tùng, Nguyễn Thanh Hường, Nguyễn Thị Ngọc Anh, The 11th Vietnam National Conference on Solid State Physics and Materials Science (SPMS-2019), Nov 2-4, 2019, Quy Nhon, Binh Dinh, Vietnam (POSTER)
4.    “Khả năng điều biến dị hướng từ vuông góc trong màng mỏng đa lớp [Co/Pd]N”, T.T. Thuy Nguyen, T. Hue Nguyen, T.T. Hai Cao, H. Manh Dinh, Q. Ngan Pham, K. Tung Do, T. Huong Nguyen, T.N. Anh Nguyen, The 11th Vietnam National Conference on Solid State Physics and Materials Science (SPMS-2019), Nov 2-4, 2019, Quy Nhon, Binh Dinh, Vietnam (POSTER)
5.    “Nghiên cứu tính dị hướng từ và sự phụ thuộc của trường trao đổi dịch theo phương vuông góc của màng mỏng đa lớp”, Nguyễn Thị Ngọc Anh, Phạm Quang Ngân, Đỗ Khánh Tùng, Nguyễn Thanh Hường, Vũ Hồng Kỳ, Phạm Hoài Linh, Cao Thị Thanh Hải, Nguyễn Thị Thanh Thủy, Nguyễn Thị Huế, Đinh Hùng Mạnh, the 11th Vietnam National Conference on Solid State Physics and Materials Science (SPMS-2019), Nov 2-4, 2019, Quy Nhon, Binh Dinh, Vietnam (INVITED)
6.    “Tunable perpendicular anisotropy and out-of-plane exchange bias in metallic multilayers”, T.N. Anh Nguyen, K. Tung Do, T. Huong Nguyen, H. Ky Vu, D. Lam Vu, Johan Åkerman, Julia Fedotova, Julia Kasiuk, Wen-Bin Wu, Janusz Przewoźnik, Czesław Kapusta, Olga Kupreeva, Serguei Lazarouk, Joint 5th International Symposium on Frontiers in Materials Science and 3rd International Symposium on Nanomaterials (FMS-NANOMATA2019), Technology and Applications, 11-12 Nov, 2019, Da Nang, Vietnam (INVITED).