Supravodljivost u nanostrukturama od zlata s mrežom tankog filma niobija

master's thesis

• Title (english): Superconductivity in gold nanostructures with a thin film niobium network
• Author: Alen Fluksek
• Mentor: Emil Tafra (mentor)
• Committee member: Emil Tafra (predsjednik povjerenstva)
• Committee member: Denis Sunko (član povjerenstva)
• Committee member: Ivan Kokanović (član povjerenstva)
• Committee member: Ivan Kupčić (član povjerenstva)
• Committee member: Mihael Srđan Grbić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Science; (Department of Physics); Zagreb
• Defense date and country: 2023-09-22, Croatia
• Scientific / art field, discipline and subdiscipline: NATURAL SCIENCES; Physics

Abstract

Proučavamo supravodič-metal prijelaz (SMP) u nanostrukturama od zlata s mrežom tankog filma niobija. Uzorke karakterizira parametar perkolacije p. Mjerenje i analiza provedeni su na šest uzoraka. Za sve uzorke smo izmjerili ovisnost otpora o temperaturi s i bez primjene magnetskog polja kao i njihove IV karakteristike. Analizom R(T) grafova odredili smo vrijednosti otpora u normalnom stanju te temperature supravodljivih prijelaza. Osim toga smo primijetili i zanimljivu anomaliju za koju smo pretpostavili da je potpis proximity efekta. Gornje kritično magnetsko polje dobiveno je ekstrapolacijom WHH i Gorter-Casimir jednadžbi. Provedena je i analiza skaliranja, varijacijom magnetskog polja, iz koje smo dobili vrijednosti produkata kritičnih eksponenata. Na temelju tih vrijednosti odredili smo klase univerzalnosti uzoraka.

Abstract (english)

We study the superconductor-metal transition (SMT) in gold nanostructures with a niobium thin film network. Samples are characterized by the percolation parameter p. The measurement and analysis were carried out on six samples. For all samples, we measured resistance dependence on temperature with and without magnetic field application as well as their I-V characteristics. By analyzing the R(T) graphs, we determined the resistance values in the normal state and the temperature of superconductive transitions. We also noticed an interesting anomaly that we assumed was a proximity effect signature. The upper critical magnetic field was obtained by extrapolation of WHH and Gorter-Casimir equations. A scaling analysis was carried out, by variation of magnetic field, from which we obtained the values of products of critical exponents. Based on these values, we’ve determined the universality classes of the samples.

• Keywords: supravodljivost; niobij; perkolacija; proximity efekt; gornje kritično magnetsko polje; analiza skaliranja
• Keywords (english): superconductivity; niobium; percolation; proximity effect; upper critical magnetic field; scaling analysis
• Language: croatian
• URN:NBN: urn:nbn:hr:217:501148
• Project: Number: IP-2016-06-2289; Title: Kolektivni efekti, tunelirajući i topološki transport u novim nanospojevima; Title: Collective effects, tunneling and topological transport in novel nanojunctions; Acronym: C3TiNN; Leader: Danko Radić; Jurisdiction: Croatia; Funder: HRZZ; Funding stream: IP
• Study programme: Title: The University Integrated Undergraduate and Graduate Programme in Physics; Research Physics; specializations in: Research Physics; Course: Research Physics; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: sveučilišni magistar fizike (sveučilišni magistar fizike)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2024-01-26 12:19:06