Sains Malaysiana 34(2): 67-71 (2005)

Sintesis Nanozarah Magnet Ferum (III) Oksida

dengan Kaedah Acuan Mikroemulsi

(Synthesis of Magnetic Nanoparticles of Ferum (III) Oxide

by using Microemulsion System as Template)

Chiu Wee Siang, Shahidan Radiman, R. Abd. Shukor, M.. H. Abdullah,

Khiew Poi Sim & Huang Nay Ming

Program Sains Nuklear, Pusat Pengajian Fizik Gunaan

Fakulti Sains dan Teknologi

Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor Darul Ehsan Malaysia

ABSTRAK

Sintesis nanozarah magnet ferum oksida secara acuan mikroemulsi dijalankan dalam kajian ini. Sistem mikroemulsi yang terdiri daripada esler sukrosa (SE1670S sebagai sutfaktan), heptanol (sebagai ko-sutfaktan), larutan akueus hidrazina hidrat (kepekatan yang berlainan) dan FeCl₃6H₂0 (0.5 M) disediakan. Setelah campuran tersebut dihomogenkan, kation Fe³⁺ akan diturunkan oleh hidrazina hidrat menjadi mendakan ferum dan pertumbuhan nanozarah ini dikawal oleh mikroemulsi yang bertindak sebagai acuan tindakbalas. Nano zarah ferum kemudian dipanaskan pada suhu tinggi untuk membentuk ferum oksida. Pencirian secara kualitatif dan kuantitatif dilakukan melalui teknik mikroskopi elektron transmisi (TEM), analisis penyebaran tenaga sinar-X (EDAX) dan kajian magnetometer (VSM). Menurut mikrograf TEM, nanozarah ferum oksida ini mempamerkan morfologi yang berlainan apabila kepekatan hidrazina hidrat diubah. Analisis penyebaran tenaga sinar-X menunjukkan bahawa nisbah Fe kepada 0 ialah 1.48. Ini menunjukkan bahawa ia sepadan dengan formula empirik Fe₂O₃. Lengkung histerisis yang diperolehi melalui kajian magnetometer (VSM) mempamerkan ciri ferimagnet dengan nilai pemagnetan tepu 0.3 emu/g pada 300K.

Kata kunci: nanozarah magnet, ferum (III) oksida, mikroemulsi, acuan, ester sukrosa

ABSTRACT

Synthesis of magnetic nanoparticles iron oxide was conducted using the single microemulsion method. The microemulsion system consists of sucrose ester (SE1670S as the sutfactant), heptanol (as co-sutfactant), aqueous hydrazine hydrate (different concentration) and FeCl₃6H₂0 was prepared. After the solutions have been homogenized, cations Fe³⁺ were reduced to precipitation of iron nanoparticles and this growing process was controlled by microemulsion which acts as template for chemical reaction. Iron nanoparticles were calcined at high temperature in order to form the iron oxide nanomaterials. The characterization technique includes transmission electron microscopy (TEM), energy dispersive X­-ray analysis (EDAX) and vibrating sample magnetometer (VSM). From TEM micrograph iron oxide with different morphology was produced corresponding to difference concentration of hydrazine hydrate. From the spectrum of EDAX, the empirical formula of iron oxide was 1.48 (almost equal to value of empiric formula of Fe₂O) Also, the hysterisis loop obtained from magnetometer (VSM) show that sample posses ferrimagnetic property with saturation magnetization 0.3 emu/g at 300 K.

Keywords: magnetic nanoparticules, iron (III) oxide, microemulsion, template, sucrose ester

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