Influence of thermal annealing on resistivity of metallic glasses

Orbanić, Filip (2014) Influence of thermal annealing on resistivity of metallic glasses. Diploma thesis, Faculty of Science > Department of Physics.

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Abstract

The influence of thermal annealing on the resistivity of metallic glass Zr67Co33 was studied in this work. The ribbon of the metallic glass was produced by ultra fast quenching with melt spinning method. To find crystallization temperatures, the sample of metallic glass was subjected to DSC analysis (two exotherms were found). The samples were annealed at different temperatures, chosen from DSC measurement, in the furnace for one hour. Subsequently, the temperature dependence of the sample resistance was measured by four probe method. The samples were cooled by helium refrigerator in the temperature range from 20 - 280K. The Amorphous samples shown a negative temperature coefficient of resistivity which is explained by effect of weak localization, whereas in the nanocrystalline samples annealed at higher temperatures, a positive temperature coefficient of the resistivity was observed. The samples annealed at temperatures above the first exotherm and the second exotherm in DSC picture were subjected to x-ray diffraction. It is observed that first the metastable phases are excreted which, at higher annealing temperatures, exceeding the stable phases. From the diffraction patterns the mean size of grains in the nanocrystalline samples was estimated (20 - 30nm).

Item Type: Thesis (Diploma thesis)
Keywords: metallic glass, electrical resistivity of metallic glasses
Supervisor: Kokanović, Ivan
Date: 2 July 2014
Subjects: NATURAL SCIENCES > Physics
Divisions: Faculty of Science > Department of Physics
Depositing User: Gordana Stubičan Ladešić
Date Deposited: 02 Sep 2014 12:56
Last Modified: 06 Sep 2016 15:28
URI: http://digre.pmf.unizg.hr/id/eprint/2587

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