Sains Malaysiana 38(3): 419-422

Kesan Penambahan Nano Ag Terhadap Suhu Genting dan

Pembentukan Fasa Superkonduktor  (Tl_0.85Cr_0.15)Sr₂CaCu₂O₇-_δ

(Effect of nano Ag addition on critical temperature and phase formation of  (Tl_0.85Cr_0.15)Sr₂CaCu₂O₇-_δ Superconductors)

W. Kong, A. K. Koh & R. Abd-Shukor*

School of Applied Physics, Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor D.E., Malaysia

Received: 6 June 2008 / Accepted: 8 August 2008

ABSTRAK

Superkonduktor suhu tinggi berasaskan sistem (Tl_0.85Cr_0.15)Sr₂CaCu₂O₇-Ag_x (Tl1212) dengan komposisi x = 0.0, 0.01, 0.02, 0.03 dan 0.05 telah disediakan dengan kaedah tindak balas keadaan pepejal. Rintangan elektrik terhadap suhu telah diukur dengan kaedah penduga empat titik. Suhu genting mula, T_c-mula bagi sistem Tl1212 tanpa penambahan nano Ag adalah 113 K. Penambahan nano Ag menurunkan suhu genting sampel. Corak pembelauan sinar-X menunjukkan bahawa semua sampel mempunyai fasa dominan 1212. Sampel x = 0.02 mempunyai peratusan fasa 1212 yang tertinggi iaitu 87%.

Kata kunci: Nano Ag; suhu genting; superkonduktor Tl1212

ABSTRACT

The Tl1212 type phase high temperature superconductor (Tl_0.85Cr_0.15)Sr₂CaCu₂O₇-Ag_x with x = 0.0, 0.01, 0.02, 0.03 and 0.05 have been prepared through the solid-state reaction method. Samples were characterized by the four-point probe method for electrical resistance. The results show that the onset critical temperature, T_c-onset of the non-added sample is 113 K. The addition of nano Ag decreased the critical temperature. XRD patterns showed that the Tl1212 phase is dominant in all samples. Sample with x = 0.02 has the highest percentage of Tl1212 phase, which is 87%.

Keywords: Critical temperature; nano Ag; Tl1212 superconductor

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*Corresponding author; email: ras@ukm.my