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dc.contributor.advisorÖzyüzer, Lütfien
dc.contributor.authorDemirhan, Yaseminen
dc.date.accessioned2014-07-22T13:50:59Z
dc.date.available2014-07-22T13:50:59Z
dc.date.issued2011en
dc.identifier.urihttp://hdl.handle.net/11147/3154
dc.descriptionThesis (Master)--Izmir Institute of Technology, Physics, Izmir, 2011en
dc.descriptionIncludes bibliographical references (leaves: 81-87)en
dc.descriptionText in English; Abstract: Turkish and Englishen
dc.descriptionxii, 87 leavesen
dc.description.abstractTerahertz radiation is part of the electromagnetic spectrum lying between microwaves and the far-IR. This region has frequencies ranging from 0.1 - 10 THz and wavelengths from 3 mm to 0.03 mm. We work on a frequency tunable solid state device to meet the needs of continuous, coherent, powerful terahertz emission sources that fill practically important terahertz gap. Among the cuprates, single crystal of Bi2Sr2CaCu2O8+ (Bi2212) is a potential candidate of compact solid state devices designed for generating electromagnetic waves in terahertz frequency range. Bi2212 crystals are consisting of natural arrays in the form of identical layers called intrinsic Josephson junctions (IJJ). In this study, under optimized doping conditions we aimed to investigate powerful terahertz emission. THz emission in the μW range can be obtained fabricating rectangular-shaped mesa structures on the Bi2212 crystal. In the experimental procedure, in order to obtain various doping levels, we annealed the high temperature superconducting Bi2212 single crystals at various temperatures in vacuum or under argon flow. By using the thermal evaporation, optic and electron beam lithography, ion beam etching techniques single and double mesa structures were fabricated. For the e-beam lithography process, we optimized and improved the required parameters. After the mesa fabrication, the exact dimensions of the mesas were obtained using surface profilometer and atomic force microscope. In order to characterize the Bi2212 mesas,by three probe contact c-axis resistance versus temperature (R-T), and current-voltage behavior (I -V) were measured in a He flow cryostat. Some of the hysteretic quasiparticle branches are seen in the I-V characteristics of Bi2212 crystals.en
dc.language.isoengen
dc.publisherIzmir Institute of Technologyen
dc.rightsinfo:eu-repo/semantics/openAccessen_US
dc.subject.lcshTerahertz spectroscopyen
dc.subject.lcshSuperconductorsen
dc.subject.lcshLithography, Electron beamen
dc.titleFabrication of double mesa structures from superconducting Bi2Sr2CaCu2O8+d by e-beam lithography for terahertz emissionen
dc.typemasterThesisen
dc.contributor.authorIDTR132915
dc.contributor.departmentIzmir Institute of Technology. Physicsen
dc.relation.publicationcategoryTezen_US


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