Sains Malaysiana 42(8)(2013): 1145–1149

Morfologi dan Sifat Magnet Filem La_1-×Sr_×MnO₃ (0 ≤ × ≤ 0.25) di Atas Substrat Kuarza

(Morphology and Magnetic Properties of La1_-×Sr_×MnO₃ (0 ≤ × ≤ 0.25) Films on Quartz Substrates)

Zalita Zainuddin

Pusat Pengajian Fizik Gunaan, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia

43600 Bangi, Selangor D.E.  Malaysia

Huda Abdullah*& Mohd Syafiq Zulfakar

Jabatan Kejuruteraan Elektrik, Elektronik dan Sistem, Fakulti Kejuruteraan dan Alam Bina

Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor D.E. Malaysia

Sahbudin Shaari

Institut Kejuruteraan Mikro dan Nanoelektronik (IMEN), Universiti Kebangsaan Malaysia

43600 Bangi, Selangor D.E., Malaysia

Diserahkan: 13 Jun 2012 /Diterima: 16 Disember 2012

ABSTRAK

Sampel larutan kompleks La1_-×Sr_×MnO₃ (LSMO) dengan 0 ≤ × ≤ 0.25 telah disediakan menggunakan kaedah Pechini. Larutan LSMO seterusnya dimendapkan ke atas substrat kuarza menggunakan kaedah salutan berputar dan seterusnya disepuh lindap pada suhu 750°C selama satu jam. Corak pembelauan sinar-X bagi filem yang mengandungi Sr bersesuaian dengan LSMO berstruktur rombohedral . Morfologi permukaan filem menunjukkan struktur yang berlainan bagi nilai × yang berlainan dengan lebih banyak pembentukan rekahan permukaan filem dengan peningkatan Sr. Sifat magnet pada suhu bilik menunjukkan kewujudan lengkungan histeresis untuk kesemua sampel. Sampel filem nipis La1_-xSr_xMnO₃ dengan × = 0.00, 0.05 dan 0.10 menunjukkan sifat feromagnet yang lemah manakala filem dengan × = 0.15, 0.20 dan 0.25 adalah bersifat paramagnet. Sampel dengan ×= 0.10 mempunyai nilai pemagnetan yang paling tinggi pada medan 12 kOe iaitu 0.48 emu/g.

Kata kunci: Kaedah Pechini; manganit; rombohedral

ABSTRACT

Samples of La1_-×Sr_×MnO₃ (LSMO) complex solution with 0 ≤ × ≤ 0.25 were prepared using the Pechini method. The LSMO solution was then deposited on a quartz substrate using the spin coating technique and annealed at 750°C for an hour. The X-ray diffraction pattern for films with Sr matches with the rhombohedral structure. The surface morphology of the film shows a different structure for a different × with more surface crack formation with Sr increment. The magnetic properties at room temperature showed hysteresis curves for all samples. La1_-xSr_xMnO₃ thin film samples with × = 0.00, 0.05 and 0.10 showed weak ferromagnetic properties while films with × = 0.15, 0.20 and 0.25 are paramagnetic. The sample with × = 0.10 has the highest magnetization value at 12 kOe, which is 0.48 emu/g.

Keywords: Manganite; Pechini method; rhombohedral

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