Jiayi Tang , Okkyun Seo , Jaemyung Kim , Ibrahima Gueye , L.S.R. Kumara , Ho Jun Oh , Wan-Gil Jung , Won-Jin Moon , Yong Tae Kim , Satoshi Yasuno , Tappei Nishihara , Akifumi Matsuda , Osami Sakata
{"title":"氧分压控制下超光滑Ti2O3和TiO2薄膜在低生长温度下的选择性相生长","authors":"Jiayi Tang , Okkyun Seo , Jaemyung Kim , Ibrahima Gueye , L.S.R. Kumara , Ho Jun Oh , Wan-Gil Jung , Won-Jin Moon , Yong Tae Kim , Satoshi Yasuno , Tappei Nishihara , Akifumi Matsuda , Osami Sakata","doi":"10.1016/j.apsadv.2025.100706","DOIUrl":null,"url":null,"abstract":"<div><div>The selective phase growth of Ti-based oxide thin films on sapphire substrates is crucial in controlling the electronic properties, such as the insulator-to-metal transition (IMT). Thin films are generally prepared by pulsed laser deposition under high temperatures, but it is challenging to obtain a smooth surface. In this study, we deposited ultra-smooth epitaxial TiO<sub>2</sub> and Ti<sub>2</sub>O<sub>3</sub> thin films with roughnesses below 0.34 Å on sapphire substrates. By controlling the oxygen partial pressure at a relatively low temperature, at 473 K, we obtained highly crystalline thin films with selective growth. The thin films grown at 1 and 10<sup>−3</sup> Pa exhibited a rutile-type TiO<sub>2</sub> phase, and those grown at 10<sup>−6</sup> Pa exhibited a hexagonal Ti<sub>2</sub>O<sub>3</sub> phase. The crystal structures and electronic structures were consistent with the previous reports on TiO<sub>2</sub> and Ti<sub>2</sub>O<sub>3</sub> thin films. Moreover, Ti<sub>2</sub>O<sub>3</sub> underwent an IMT, whereas TiO<sub>2</sub> was unchanged.</div></div>","PeriodicalId":34303,"journal":{"name":"Applied Surface Science Advances","volume":"26 ","pages":"Article 100706"},"PeriodicalIF":8.7000,"publicationDate":"2025-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Selective phase growth of ultra-smooth Ti2O3 and TiO2 thin films at low growth temperature controlled by the oxygen partial pressure\",\"authors\":\"Jiayi Tang , Okkyun Seo , Jaemyung Kim , Ibrahima Gueye , L.S.R. Kumara , Ho Jun Oh , Wan-Gil Jung , Won-Jin Moon , Yong Tae Kim , Satoshi Yasuno , Tappei Nishihara , Akifumi Matsuda , Osami Sakata\",\"doi\":\"10.1016/j.apsadv.2025.100706\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The selective phase growth of Ti-based oxide thin films on sapphire substrates is crucial in controlling the electronic properties, such as the insulator-to-metal transition (IMT). Thin films are generally prepared by pulsed laser deposition under high temperatures, but it is challenging to obtain a smooth surface. In this study, we deposited ultra-smooth epitaxial TiO<sub>2</sub> and Ti<sub>2</sub>O<sub>3</sub> thin films with roughnesses below 0.34 Å on sapphire substrates. By controlling the oxygen partial pressure at a relatively low temperature, at 473 K, we obtained highly crystalline thin films with selective growth. The thin films grown at 1 and 10<sup>−3</sup> Pa exhibited a rutile-type TiO<sub>2</sub> phase, and those grown at 10<sup>−6</sup> Pa exhibited a hexagonal Ti<sub>2</sub>O<sub>3</sub> phase. The crystal structures and electronic structures were consistent with the previous reports on TiO<sub>2</sub> and Ti<sub>2</sub>O<sub>3</sub> thin films. Moreover, Ti<sub>2</sub>O<sub>3</sub> underwent an IMT, whereas TiO<sub>2</sub> was unchanged.</div></div>\",\"PeriodicalId\":34303,\"journal\":{\"name\":\"Applied Surface Science Advances\",\"volume\":\"26 \",\"pages\":\"Article 100706\"},\"PeriodicalIF\":8.7000,\"publicationDate\":\"2025-02-08\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Applied Surface Science Advances\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S2666523925000157\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Applied Surface Science Advances","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2666523925000157","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Selective phase growth of ultra-smooth Ti2O3 and TiO2 thin films at low growth temperature controlled by the oxygen partial pressure
The selective phase growth of Ti-based oxide thin films on sapphire substrates is crucial in controlling the electronic properties, such as the insulator-to-metal transition (IMT). Thin films are generally prepared by pulsed laser deposition under high temperatures, but it is challenging to obtain a smooth surface. In this study, we deposited ultra-smooth epitaxial TiO2 and Ti2O3 thin films with roughnesses below 0.34 Å on sapphire substrates. By controlling the oxygen partial pressure at a relatively low temperature, at 473 K, we obtained highly crystalline thin films with selective growth. The thin films grown at 1 and 10−3 Pa exhibited a rutile-type TiO2 phase, and those grown at 10−6 Pa exhibited a hexagonal Ti2O3 phase. The crystal structures and electronic structures were consistent with the previous reports on TiO2 and Ti2O3 thin films. Moreover, Ti2O3 underwent an IMT, whereas TiO2 was unchanged.