Pengaruh Variasi Holding Time pada Sintesis Superkonduktor Mgb2 dengan Penambahan Nikel Menggunakan Metode Powder in Sealed Tube

Abstract

Telah dilakukan penelitian tentang pengaruh holding time pada sintesis material superkonduktor MgB2 dengan penambahan nikel menggunakan metode powder in sealed tube. MgB2 adalah superkonduktor yang memiliki temperatur kritis ~39 K. Penambahan Ni sebesar 0%, 4% dan 8% untuk mempelajari pengaruhnya terhadap karakteristik superkonduktivitas MgB2. Proses preparasi sampel dimulai dengan menimbang bahan baku berupa serbuk Mg, B dan Ni sesuai perhitungan stoikiometri. Bahan tersebut kemudian digerus selama 1 jam menggunakan mortar agate lalu dimasukkan kedalam tabung stainless steel tipe SS 316L dan dilakukan proses pressing PIST dengan tekanan 5 MPa, selanjutnya dilakukan proses sintering menggunakan muffle furnace dengan suhu 800º dan holding time suhu sinter selama 1 jam, 3 jam dan 5 jam. Sampel dikarakterisasi dengan alat XRD, SEM-EDS dan Cryogenic Magnet. Hasil identifikasi fasa melalui XRD menunjukkan fasa-fasa yang terbentuk antara lain MgB2, MgNi2.5B2, MgO, Mg dan Ni. Struktur morfologi dan komposisi unsur dilihat melalui SEM-EDS. Dari pengujian Cryogenic Magnet, sampel MgB2 murni dengan holding time 1 jam memiliki temperatur kritis Tc onset (36,29 K) dan tidak memiliki Tczero. Sedangkan untuk MgB2 murni pada holding time 5 jam memiliki Tconset (42,18 K) dan Tc Zero sebesar (25,55 K)

Research of the effect holding time on synthesis of Magnesium Diboride (MgB2) superconductor with the addition of Nikel (Ni) using powder in sealed tube method has been done. MgB2 superconductors has critical temperature ~39K. The addition of Ni 0%, 4% and 8% conducted to study its effect on characteristic against superconductivity in MgB2. The sample preparation process begin with weigh the raw material form of powder Mg, B and Ni based on the calculation stoiciometry. Then the materials is milled during 1 hour using mortar agate and the inserted into the type of SS 316L stainless steel tube and do a pressing process with a pressure of 5 MPa, furthermore do sintering process using muffle furnance at temperature 800ºC and holding time during 1 hour, 3 hour and 5 hour. The samples were characterized by means of XRD, SEM-EDS and Cryogenic Magnet. Phase identification seen by XRD, there are several phases that from such as, MgB2, MgNi2.5B2, MgO, Mg and Ni. The structure of morphology and composition of elements seen through SEM-EDS. Based of testing of Cryogenic Magnet, pure MgB2 with holding time during 1 hour has indicates temperature, Tc onset (36,29 K) and has not Tczero. While for pure MgB2 with holding time during 5 hour has indicates temperature Tconset (42,18 K) and Tc Zero (25,55).