Sains Malaysiana 41(8)(2012): 1029–1035

Effect of Different TiO₂ Preparation Techniques on the Performance of the Dielectric

Bolometer Ba₀₆Sr_0.4TiO₃ as a Distance Sensor

(Kesan Kaedah Penyediaan TiO₂ yang Berbeza Terhadap Prestasi Bolometer

Dielektrik Ba₀₆Sr_0.4TiO₃ sebagai Pengesan Jarak)

N.B. Ibrahim*, E. Yusrianto & Z. Ibarahim

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

43600 Bangi, Selangor, Malaysia

Diserahkan: 25 Januari 2010 / Diterima: 25 Mac 2011

ABSTRACT

In this study TiO₂ films have been prepared using two different techniques i.e. sol-gel and electron gun evaporation (e-gun) techniques. The films were annealed at 300, 350 and 400^oC in air. The microstructure study using field emission scanning electron microscopy and x-ray diffractometer showed nanometer grains size and only the film prepared by sol-gel and annealed at 400^oC has anatase phase while others are amorphous. To study the effect of the films (as buffer layer) onto the dielectric bolometer Ba_0.6Sr_0.4TiO₃ as distance sensor, sensors with the configuration of Al/BST/TiO₂/RuO₂/SiO₂/Si were built. Two different measurements i.e. with and without infrared source were carried out to measure the sensitivity and repeatability of the sensors. The sensors which contained sol-gel TiO₂ films gave reading for both type of measurements, indicating that the sensor can act as active and passive sensors. However, the sensors which contained e-gun TiO₂ films only gave responses when the IR source was used, indicating that they can only act as passive sensors. The most sensitive sensor was TiO₂ film prepared by sol gel and annealed at 350^oC. In general sensors

which contained TiO₂ films prepared by sol gel showed good repeatability.

Keywords: Sol-gel; thin film; TiO₂

ABSTRAK

Dalam kajian ini, filem TiO₂ telah disediakan dengan dua teknik yang berbeza iaitu teknik sol-gel dan penyejatan senapang elektron (senapang-e). Filem kemudiannya disepuhlindap pada 300, 350 dan 400^oC dalam udara biasa. Kajian mikrostruktur menggunakan mikroskop elektron imbasan pemancaran medan (FE-SEM) dan pembelauan sinar-X menunjukkan kesemua filem mempunyai saiz butiran nanometer dan hanya filem yang disediakan dengan sol-gel dan disepuhindap pada 400^oC mempunyai fasa anatas sementara yang lain adalah amorfus. Untuk mengkaji kesan filem tersebut (sebagai lapisan penimbal) ke atas bolometer dielektrik Ba_0.6Sr_0.4TiO₃ sebagai pengesan jarak, sensor dengan konfigurasi Al/BST/TiO₂/RuO₂/SiO₂/Si telah dibina. Dua pengukuran yang berbeza iaitu dengan dan tanpa punca inframerah telah dijalankan untuk mengukur kesensitifan dan kebolehulangan pengesan. Pengesan yang mengandungi filem TiO₂ sol-gel memberikan bacaan untuk kedua-dua jenis pengukuran, menandakan pengesan ini boleh bertindak sebagai pengesan aktif dan pasif. Namun begitu, pengesan yang mengandungi filem TiO₂ senapang-e hanya memberi tindak balas apabila punca inframerah digunakan, menandakan pengesan hanya boleh bertindak sebagai pengesan pasif. Pengesan yang paling sensitif adalah pengesan dengan filem TiO₂ yang disediakan dengan sol-gel dan disepuhindap pada 350^oC. Secara amnya pengesan yang mengandungi filem TiO₂ yang disediakan dengan sol-gel menunjukkan kebolehulangan yang baik.

Kata kunci: Filem nipis; sol-gel; TiO₂

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