Sains Malaysiana 41(9)(2012): 1125–1131

 

 

Structural and Magnetic Properties of Type-M Barium Ferrite – Thermoplastic Natural Rubber Nanocomposites

(Sifat Struktur dan Magnet Nanokomposit Ferit Barium Jenis-M – Getah Asli Termoplastik)

 

 

Nurhidayaty Mokhtar

Physics Department, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang

Selangor D.E. Malaysia

 

Mustaffa Hj. Abdullah* & Sahrim Hj. Ahmad

School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor D.E. Malaysia

 

Diserahkan: 29 Jun 2011 / Diterima: 29 Februari 2012

 

ABSTRACT

Structural and magnetic properties of type-M barium ferrite (BaFe12O19) nanoparticles (~ 20 nm) embedded in non-magnetic thermoplastic natural rubber (TPNR) matrices were investigated. The TPNR matrices were prepared from high density polyethylene (HDPE) and natural rubber (NR) in the weight ratios of 80:20 and 60:40, respectively, with 10 wt% of NR in the form of liquid natural rubber (LNR) which act as a compatibiliser. BaFe12O19 – filled nanocomposites with 2 – 12 wt% BaFe12O19 ferrite were prepared using a melt- blending technique. Magnetic hysteresis was measured using a vibrating sample magnetometer (VSM) in a maximum field of 10 kOe at room temperature (25oC). The saturation magnetisation (MS), remanence (MR) and coercivity (Hc) were derived from the hysteresis loops. The results show that the structural and magnetic properties of nanocomposites depend on both the ferrite content and the composition of the natural rubber or plastic in the nanocomposites. All the nanocomposites exhibit an exchange bias-like phenomenon resulting from the exchange coupling of spins at the interface between the core ferrimagnetic region and the disordered surface region of the nanoparticles.

 

Keywords: Exchange bias; high density polyethylene; hysteresis; magnetic properties; natural rubber

 

ABSTRAK

Sifat struktur dan magnet nanozarah (~ 20 nm) ferit barium jenis-M (BaFe12O19) yang dimasukkan ke dalam matriks getah asli termoplastik (TPNR) tidak bermagnet telah dikaji. Matrik TPNR disediakan daripada polietilena ketumpatan tinggi (HDPE) dan getah asli (NR) dalam nisbah berat 80:20 dan 60:40, dengan 10% berat NR dalam keadaan getah asli cecair (LNR) yang bertindak sebagai penserasi. Nanokomposit berpengisi BaFe12O19 sebanyak 2 – 12% berat disediakan menggunakan teknik adunan lebur. Histeresis magnet diukur menggunakan magnetometer sampel bergetar (VSM) dalam medan maksimum 10 kOe pada suhu bilik (25oC). Pemagnetan tepu (Ms), remanens (MR) dan koersiviti (Hc) diperoleh daripada gelung histeresis. Keputusan menunjukkan bahawa sifat struktur dan magnet nanokomposit bergantung kepada kandungan ferit dan komposisi getah asli atau plastik dalam nanokomposit. Semua nanokomposit menunjukkan fenomenon mirip pincang saling tukar yang terhasil daripada gandingan saling tukar pada antaramuka di antara rantau teras ferimagnet dan rantau tak tertib di permukaan nanozarah.

 

Kata kunci: Getah asli; histeresis; pincang saling tukar; polietilena ketumpatan tinggi; sifat magnet

 

 

RUJUKAN

Abdullah, M.H., Ahmad, M., Ibrahim, N.B. & Yusoff, A.N. 2008. Microwave magnetic, dielectric and absorption properties of some cerium yttrium iron garnets. Sains Malaysiana37(2): 205-2010.

Berkowitz, A.E., Lahut, J.A., Jacos, I.S., Levinson, C.M. & Forester, D.W. 1975. Spin Pinning at Ferrite-Organic Interfaces. Physical Review Letters 34: 594-598.

Berkowitz, A.E., Lahut, J.A. & Van Buren, C.E. 1980. Properties of magnetic fluid particles. IEEE Transactions on Magnetics, MAG-16: 184-190.

Hajra, P., Basu, S., Brahma, P. & Chkravorty, D. 2009. Exchange bias in ferromagnetic-antiferromagnetic nanocomposite produced by mechanical attrition. Journal of Magnetism and Magnetic Materials. 321(14): 2269-2275.

Hamid, S.A.A., Abdullah, M.H., Ahmad, S.H., Jusoh, Mansor, A.A. & Yusoff, A.N. 2002. Effects of natural rubber on microwave absorption characteristics of some Li-Ni-Zn ferrite – thermoplastic natural rubber composites. Japanese Journal of Applied Physics, 41: 5815-5820.

Hamid, S.A.A., Abdullah, M.H., Ahmad, S.H., Jusoh, Mansor, A.A. & Yusoff, A.N. 2002. Structural and morphologyical properties of Li-Ni-Zn frrite – TPNR composites. Journal of Solid State Science and Technology Letters 9(1): 68-73.

Kodama, R.H., Berkowitz, A.E., McNiff, E.J. & Foner, S. 1996. Surface Spin Disorder in NiFe2O4 Nanoparticles. Physical Review Letters 77: 394-397.

Kojima, H. 1982. Fundamental properties of hexagonal ferrites with magnetoplumbite structure. In Ferromagnetic Materials, edited by E.P. Wohlfarth. New York: North-Holland Publishing Company.

Kong, I., Ahmad, S.H., Abdullah, M.H., Hue, D., Yusoff, A.N. & Puryanti, D. 2010. Magnetic and microwave absorbing properties of magnetite – thermoplastic natural rubber nanocomposites. Journal of Magnetism and Magnetic Materials 322: 3401- 3409.

Misra, R.D.K., Gubbala, S., Kale, A. & Egelhoff, Jr, W.F. 2004. A comparison of the magnetic characteristics of nanocrystalline nickel, zinc, and manganese ferrites synthesized by reverse micelle technique. Materials Science and Engineering B 111(2-3): 164-174.

Nogues, J., Sort, J., Langlais, V., Skumryev, V., Surinach, S., Munoz, J.S. & Baro, M.D. 2005. Exchange bias in nanostructure. Physics Reports 422(3): 65-117.

Puryanti, D., Ahmad, S.H., Abdullah, M.H. & Yusoff, A.N. 2007. Effect of nickel-cobalt-zinc ferrite filler on magnetic and thermal properties of thermoplastic natural rubber composites. International Journal of Polymeric Materials 56: 1-12.

Puryanti, D., Ahmad, S.H., & Abdullah, M.H. 2006. Effect of Nickel-Cobalt-Zinc Filler on Electrical and Mechanical Properties of Thermoplastic Natural Rubber Composites Polymer – Plastics Technology and Engineering 45: 561-567.

Rane, M.V., Bahadur, D., Nigam, A.K. & Srivastava, C.M. 1999. Mossbauer and FT-IR studies on non-stoichiometric barium hexaferrites. Journal of Magnetism and Magnetic Materials 192(2): 288-296.

Rezlescue, L., Rezlescue, E., Popa, P.D. & Rezlescue, N. 1999. Fine barium hexaferrite powder prepared by the crystallization of glass. Journal of Magnetism and Magnetic Materials 193(1-3): 288-290.

Yusoff, A.N., Abdullah, M.H., Ahmad, S.H., Jusoh, S.F., Mansor, A.A. & Hamid, S.A.A. 2002. Electromagnetic and absorption properties of some microwave absorgers. Journal of Applied Physics 92: 876-882.

 

*Pengarang untuk surat-menyurat; email: mha@ukm.my