Azwar Manaf, Dr. Department of Physics

Dr Azwar Manaf is a permanent academic staff at the Department of Physics, Faculty of Mathematics and Natural Sciences, Universitas Indonesia. He received his Drs (BS) in Physics from Gadjah Mada University in 1982, his master’s degree in Material and Metallurgical Engineering from KU Leuven, Belgium, in 1987, and another master’s degree (in 1988) and a PhD (in 1992) from School of Materials Engineering, University of Sheffield, UK.

Expertise and current research interests:

Dr. Manaf is an expert and active researcher in the field of magnetism for permanent magnet applications. Recently, he has extended his interest to include the application of soft magnetic materials for radar absorbers.

Major research achievements:

One of the significant breakthrough in Dr. Manaf’s research works is his report on the New nanocrystalline high-remanence Nd-Fe-B alloys by rapid solidification, that was published in Journal of Magnetism and Magnetic Materials 128, 302–306 (1993). The very strong enhancement of remanent magnetization results from the grain exchange coupling effect due to nanostructure development during the rapid solidification process by melt-spinning technique. This finding was obtained through a systematic investigation of the effects of grain refinement into the nanocrystalline regime in enhancing the remanence and maximum energy product, (BH)_max performed for Nd-Fe-B materials with small silicon additions. This was then extended to ternary low Nd near-stoichiometric alloys, and eventually the effect was shown to be general, provided that the grains are magnetically coupled. His discovery is believed to be highly significant from the fundamental and technological viewpoints. Scientifically, he demonstrated that the nanostructure in magnetic materials that promotes grain interaction lead to remanent magnetization above the theoretical value based on Stoner and Wohlfarth, SW theory. This was apparently in contravention of the theory which states that, for randomly oriented, non-interacting magnetic particles having uniaxial anisotropy, the ratio of remanent to saturation magnetization less than or equal to 0.5. His description to this phenomenon was initially disbelieved by magnetic “community” though, subsequently, similar behaviour was also reported by a research group of Phillips for a very low Nd containing alloys. The effects have now been widely accepted since more research groups of both experimental and theoretical have confirmed these results. Technologically, materials with nanostructures are commercially very attractive since, provided the nanocrystalline structures are equivalent to that described in Dr. Manaf’s report on Ne-Fe-B, remanence enhancements can be achieved by overquenching and annealing so that materials can be produced in bulk for polymer-bonded magnets.

Dr. Azwar Manaf is the author and co-author of more than 20 internationally published papers regarding magnetic materials alone. He is also the holder of European Patent No. EP 0650 634 B1, Assignee : University of Sheffield, “Magnetic Materials and Methods of Making Them” published on 27/3/1996. It is also noticed that at the international scientific meetings on magnetic materials as well as scientific papers in international journals related to magnetic materials, many researchers have cited Dr. Manaf’s research works in their references. He was also awarded a Brunton Medal by the University of Sheffield United Kingdom for his excellent research works in 1992. Universitas Indonesia has also awarded him certificates/prizes as Peneliti Muda Berprestasi of FMIPA, Univ. Indonesia in 1995 and the best senior researcher of Universitas Indonesia in 2001. See his CV at http://matsci.fisika.ui.ac.id/lecturer/azwar.htm for details.

Selected Publications: [See publication in Scopus]

S. Budi, B. Kurniawan, D. M. Mott, S. Maenosono, A. A. Umar, A. Manaf, Comparative trial of saccharin-added electrolyte for improving the structure of an electrodeposited magnetic FeCoNi thin film, Thin Solid Films 642, 51-57 (2017).
W.A. Adi, A. Manaf, Ridwan, Absorption characteristics of the electromagnetic wave and magnetic properties of the La0.8Ba0.2Fexmn1/2(1-X)Ti1/2(1-X)O3(X = 0.1-0.8) Perovskite system, International Journal of Technology 8(5), pp. 887-897 (2017).
B. Kurniawan, S. Winarsih, A. Imaduddin, A. Manaf, Correlation between microstructure and electrical transport properties of La0.7(Ba1-xCax)0.3MnO3 (x = 0 and 0.03) synthesized by sol-gel, Physica B: Condensed Matter 2017 (in Press).
A. Manaf, M.A.E. Hafizah, Belyamin, B. Nainggolan, M. Manawan, Magnetic and microwave absorption characteristics of TI2+-MN4+substituted barium hexaferrite, International Journal of Technology 8(3), 458-465 (2017).
E. Yustanti, M.A.E. Hafizah, A. Manaf, Exploring the effect of particle concentration and irradiation time in the synthesis of barium strontium titanate (BST) Ba(1-X)SrXTiO3(X:0-1) nanoparticles by high power ultrasonic irradiation, International Journal of Technology 7(6), 1016-1025 (2016).
Novizal, A. Manaf, M.C. Fajrah, The effect of induced magnetic anisotrophy on the hysteresis parameter of nano barium strontium haxaferrite prepared by mechanical alloying and sonication, International Journal of Technology 7(3), 486-492 (2016).
E. Panjaitan, A. Manaf, B. Soegijono, E. Kartini, Effect of Additional Poly Vinyledene Fluoride (PVDF) on LiCoO2 Cathodes, Procedia Chemistry 4, 60–64 (2012).
A. Manaf and V. Indrawati, Portland-Blended Cement with Reduced CO2 using Trass Pozzolan, Journal of the Korean Chemical Society 55, 490-494 (2011).
A. Manaf, R.A. Buckley, H.A. Davies, New nanocrystalline high-remanence Nd-Fe-B alloys by rapid solidification, Journal of Magnetism and Magnetic Materials 128, 302–306 (1993) [Highly cited paper: Scopus, Google ].
A. Manaf, M. Al-Khafaji, P.Z. Zhang, H.A. Davies, R.A. Buckley, W.M. Rainforth, Microstructure analysis of nanocrystalline Fe-Nd-B ribbons with enhanced hard magnetic properties, Journal of Magnetism and Magnetic Materials 128, 307–312 (1993).
A. Manaf, R.A. Buckley, H.A. Davies, M. Leonowicz, Enhanced magnetic properties in rapidly solidified Nd-Fe-B based alloys, Journal of Magnetism and Magnetic Materials 101, 360–362 (1991) [Highly cited paper: Scopus, Google ].