Effects of synthesis conditions on the transition metal dichalcogenide TiSe2
| dc.contributor.advisor | Morosan, Emilia | |
| dc.creator | Moya, Jaime M | |
| dc.date.accessioned | 2020-04-27T21:09:37Z | |
| dc.date.available | 2020-04-27T21:09:37Z | |
| dc.date.created | 2020-05 | |
| dc.date.issued | 2020-04-24 | |
| dc.date.submitted | May 2020 | |
| dc.date.updated | 2020-04-27T21:09:37Z | |
| dc.description.abstract | TiSe2 is part of a family of materials known as the transition metal dichalcogenides. Their quasi-two dimensional crystal structure sometimes gives rise to interesting phenomena, spanning a vast array physical and electronic properties including charge order or superconductivity when various intercalants or dopants are added. TiSe2 was shown to have charge ordering at a temperature of 200 K almost 45 years ago. Despite the time that has elapsed between this discovery and now, TiSe2 continues to be an intensely studied material because the nature of its charge ordering is still under debate. Some of the contradicting results are fueled by sample dependency related to growth method and conditions. Because of the small band gap or band overlap in TiSe2, it is not surprising that dilute impurities and growth conditions can drastically aect the transport properties of TiSe2. In this work, I systematically study the effect of variable growth conditions including post synthesis cooling rate, anneal time, and temperature, on the electrical resistivity of TiSe2. I find that slow cooling polycrystalline TiSe2 post synthesis drastically increases the low temperature resistivity, which is in stark contrast to the metallic low temperature resistivity observed in single crystalline TiSe2 grown by iodine vapor transport, where the iodine charge dopes the sample. Together, the logarithmic divergence of the resistivity and signatures in low temperature magnetoresistance point to signatures of the weak-localization effect. Annealing samples at low temperatures post synthesis also increase the low temperature resistivity, but with a less profound aect. Finally, quenching samples from high temperature, freezes in disorder, and decreases the low temperature resistivity. | |
| dc.format.mimetype | application/pdf | |
| dc.identifier.citation | Moya, Jaime M. "Effects of synthesis conditions on the transition metal dichalcogenide TiSe2." (2020) Master’s Thesis, Rice University. <a href="https://hdl.handle.net/1911/108429">https://hdl.handle.net/1911/108429</a>. | |
| dc.identifier.uri | https://hdl.handle.net/1911/108429 | |
| dc.language.iso | eng | |
| dc.rights | Copyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder. | |
| dc.subject | TiSe2 | |
| dc.subject | transition metal dichalcogenide | |
| dc.title | Effects of synthesis conditions on the transition metal dichalcogenide TiSe2 | |
| dc.type | Thesis | |
| dc.type.material | Text | |
| thesis.degree.department | Applied Physics | |
| thesis.degree.discipline | Natural Sciences | |
| thesis.degree.grantor | Rice University | |
| thesis.degree.level | Masters | |
| thesis.degree.major | Applied Physics/Physics | |
| thesis.degree.name | Master of Science |
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