Prof. Dede Djuhana, M.Si., Ph.D. who is the Dean of the Faculty of Mathematics and Natural Sciences (FMIPA) Universitas Indonesia (UI) was inaugurated as Permanent Professor in the Field of Materials Science FMIPA UI, on Wednesday (15/11), at the UI Depok Campus Convention Hall. The inauguration procession, which was broadcasted live via the UI YouTube channel and UI Teve, was led directly by the UI Rector, Prof. Ari Kuncoro, S.E., M.A., Ph.D.
In a scientific oration entitled “Application of Micromagnetic Simulation in Research on the Structure and Domain Dynamics of Ferromagnetic Materials”, Prof. Dede said that data storage devices have become an important requirement for documentation purposes in the current digital era. A hard-disk drive (HDD) type data storage device is a type of data storage that is popular among the public for its affordable price, large capacity, and durability over a certain period of time. In general, HDD type data storage is still popular, even though solid-state drives (SSD) currently are widely used as data storage.
Prof. Dede sees challenges in the magnetic media recording process in the future. These challenges include writability, signal-to-noise, and thermal stability. In addition, magnetic media recording using conventional technology has a capacity limit, namely an average of 1 Tb/in2.
To increase magnetic recording capacity, new innovations can be created using patterned-media, assisted-thermal or solid state. Large capacity densities from magnetic media recording can be obtained through grain size reduction. However, reducing this size will result in the grain magnetization becoming unstable or known as the super paramagnetic limit (SPM).
Grain magnetization easily changes from one state to another due to the influence of temperature. The transition time of grain magnetization in the SPM region is known as the Néel relaxation time. This means that if you are able to control the magnetization conditions regarding thermal fluctuations in the grain, magnetization stability in the SPM area can be obtained.
“In 2008, a research group from IBM Almaden, USA, led by Stuart Parkin, published a magnetic recording device called Racetrack memory (RM). RM devices are solid-state memory, non-volatile, and are an alternative to replacing the role of SSDs in the future. The ability to control the effects of Walker breakdown and Joule heating is a challenge in developing devices for the domain structure to remain stable,” said Prof. Dede.
According to him, one of the important tools in magnetic domain structure research is micromagnetic simulation. Micromagnetics is a field of magnetism that studies the dynamic structure of magnetic domains using a Continuum approach to explain the nature and dynamics of magnetic domain structures. In the last two decades, the results of micromagnetic simulations have helped researchers in analyzing the structure of ferromagnetic domains.
Therefore, in his research, Prof. Dede carried out micromagnetic simulations using several models, namely the ball model, straight nanowire model, and notch nanowire, to observe the structure and dynamics of the magnetic domain of ferromagnetic materials. Simulations in ground state conditions provide information on the domain structure transition from single-domain (SD) to multi-domain (MD) from the system energy profile, such as demagnetization and exchange energy.
Research Prof. Dede regarding the application of micromagnetic simulation is one of the many studies he has carried out. Some of them are Investigation of Harmonic and in Harmonic Domain Wall Oscillation by Sinusoidal Magnetic Field in the Notched Permalloy Nanowire using Micromagnetic Approach (2023); Single-step Laser Ablation Synthesis of ZnO–Ag Nanocomposites for Broad-Spectrum Dye Photodegradation and Bacterial Photoinactivation (2023); and Femtosecond Laser-Induced Photochemical Synthesis of Gold Nanoparticles in Nitrate Solution (2022).
Prof. Dede Djuhana, M.Si., Ph.D. completed his bachelor’s degree (1999) and master’s degree (2003) at the Department of Physics, FMIPA UI. He earned his Ph.D. from the Department of Physics, College of Science, Chungbuk National University, Cheongju, South Korea (2009). Before serving as Dean of FMIPA UI, he served as Director of Research and Development at UI in 2020–2022.
The inauguration procession of professor of Prof. Dede was also attended by the Dean of FMIPA, Jakarta State University, Prof. Dr. Muktiningsih, M.Si.; Dean of FMIPA ITB/HFI, Prof. Wahyu Srigutomo; Head of the Magnetic Materials and Nanoparticles Research Group, Center for Advanced Materials Research, BRIN, Prof. Dr. Wisnu Ari Adi; Chairman of the Indonesian Magnetic Society, Prof. Agustinus Agung Nugroho Sulistyo Hutomo; Head of STMKG, Dr. Suko Prayitno Adi; and President Commissioner of PT Luas Birus Utama, Dr. Ir. Harris Susanto, S.Si., M.Hum.
