国产bbaaaaa片,成年美女黄网站色视频免费,成年黄大片,а天堂中文最新一区二区三区,成人精品视频一区二区三区尤物

首頁> 外文學(xué)位 >Fabrication of Ferrite Thin Film using Low Pressure Metalorganic Chemical Vapor Deposition.
【24h】

Fabrication of Ferrite Thin Film using Low Pressure Metalorganic Chemical Vapor Deposition.

機(jī)譯：使用低壓金屬有機(jī)化學(xué)氣相沉積法制備鐵氧體薄膜。

獲取原文
獲取原文并翻譯 | 示例
  • 摘要
  • 著錄項(xiàng)
  • 相似文獻(xiàn)
  • 相關(guān)主題

摘要

This thesis is based on the research work on the multiferroic material fabrications using low pressure metalorganic chemical vapor deposition (MOCVD). Multiferroic material refers to the ones who have two or more ferroic properties, like ferroelectricity, ferromagnetism, ferroelasticity and ferrotoroidicity. Extensive research findings focused on pure nano scale thin films and composites those were related to presenting both ferroelectricity and ferromagnetism coupling within the material.;BiFeO3 (BFO) was known to be the only single phase multiferroic material which exhibited magnetoelectric (ME) coupling effect at room temperature. This coupling effect provided an extra degree of freedom for designs of whole new devices and applications never thought to be possible before. Recently, large ME effect was found in its thin epitaxial-strained films. However, very few papers reported the CVD techniques for depositing BFO thin films so far. Most of these reports used direct liquid injection method to deliver the organometallic reactants during the CVD process (ie. DLICVD). Here, we introduced a novel liquid iron precursor, n-butylferrocene, delivered into the reactor by heating the precursor canisters at certain temperatures for growing BFO thin films. Other crucial MOCVD conditions (reactor's pressure, reactor's temperature, substrates...) were also discussed and optimized. Characterizations for the film composition, crystallinity, ferroelectricity, ferromagnetism and the magneto-dielectric coupling effect were analyzed in detail. The results confirmed that BFO film had multiferroic properties and could be potentially used in future tunable high-frequency devices.;Although single-phase BFO exhibited ME effect, this suffered from problems such as current leakages, weak ME coupling and low ordering temperatures. Doping or ion substitution was a limited way to enhance the ME property since the compounds had definite compositions. Therefore, heterostructures such as bilayered/multilayered thin films, nanoparticles/nanopillars embedded in different materials and nanowires became more promising for the future on-chip integration applications because the coupling in such structures was many orders of magnitude stronger. Another research scientists interested in was the heterostructural magnetostrictive NiFe2O4 (NFO) with piezoelectric materials. NFO was a promising magnetic phase for ME heterostructures due to its low anisotropy, high permeability with high resistivity, low eddy current losses and smaller coercive field. In this study, the nickel ferrite thin films had been deposited using computer controlled MOCVD setup in both co-deposition mode and cyclic-deposition mode. Conditions for CVD process were discussed and optimized for growing NFO thin film. The thin films showed NFO composition, uniformity in chemical states and thickness, trevorite crystalline form, free from carbon contamination and similar magnetic property as other literature reported.
機(jī)譯：本論文是基于對利用低壓金屬有機(jī)化學(xué)氣相沉積（MOCVD）技術(shù)制造多鐵性材料的研究工作。多鐵性材料是指具有兩種或更多種鐵性的材料，例如鐵電性，鐵磁性，鐵彈性和鐵磁性。廣泛的研究發(fā)現(xiàn)集中在與在材料中同時呈現(xiàn)鐵電和鐵磁耦合有關(guān)的純納米級薄膜和復(fù)合材料。已知BiFeO3（BFO）是唯一一種在以下溫度下表現(xiàn)出磁電（ME）耦合作用的單相多鐵性材料。室內(nèi)溫度。這種耦合效應(yīng)為全新設(shè)備的設(shè)計(jì)和應(yīng)用提供了前所未有的自由度。近來，在其薄的外延應(yīng)變膜中發(fā)現(xiàn)了大的ME效應(yīng)。然而，到目前為止，幾乎沒有論文報道了用于沉積BFO薄膜的CVD技術(shù)。這些報告中的大多數(shù)使用直接液體注入方法在CVD工藝（即DLICVD）過程中輸送有機(jī)金屬反應(yīng)物。在這里，我們介紹了一種新型的液態(tài)鐵前驅(qū)體正丁基二茂鐵，它是通過在一定溫度下加熱前驅(qū)體罐以生長BFO薄膜的方式輸送到反應(yīng)器中的。還討論并優(yōu)化了其他關(guān)鍵的MOCVD條件（反應(yīng)器的壓力，反應(yīng)器的溫度，基材等）。詳細(xì)分析了膜組成，結(jié)晶度，鐵電性，鐵磁性和磁介電耦合效應(yīng)的表征。結(jié)果證實(shí)了BFO膜具有多鐵性，并有可能在未來的可調(diào)高頻器件中使用。;盡管單相BFO表現(xiàn)出ME效應(yīng)，但存在諸如漏電，ME耦合弱和訂購溫度低等問題。摻雜或離子取代是增強(qiáng)ME性能的有限方式，因?yàn)檫@些化合物具有確定的組成。因此，異質(zhì)結(jié)構(gòu)（例如雙層/多層薄膜，嵌入不同材料的納米顆粒/納米柱和納米線）對于將來的片上集成應(yīng)用變得更有希望，因?yàn)檫@種結(jié)構(gòu)中的耦合強(qiáng)度要高很多個數(shù)量級。另一位感興趣的研究科學(xué)家是采用壓電材料的異質(zhì)結(jié)構(gòu)磁致伸縮NiFe2O4（NFO）。 NFO由于其低各向異性，高磁導(dǎo)率和高電阻率，低渦流損耗和較小的矯頑場而成為ME異質(zhì)結(jié)構(gòu)的有希望的磁相。在這項(xiàng)研究中，使用計(jì)算機(jī)控制的MOCVD裝置以共沉積模式和循環(huán)沉積模式沉積了鎳鐵氧體薄膜。討論了用于生長NFO薄膜的CVD工藝條件并對其進(jìn)行了優(yōu)化。薄膜顯示出NFO的成分，化學(xué)狀態(tài)和厚度的均勻性，三方晶的結(jié)晶形式，沒有碳污染和與其他文獻(xiàn)報道的相似的磁性。

著錄項(xiàng)

  • 作者

    Yang, Yi.;

  • 作者單位

    University of Illinois at Chicago.;

  • 授予單位 University of Illinois at Chicago.;
  • 學(xué)科 Engineering Chemical.;Engineering General.;Nanotechnology.
  • 學(xué)位 Ph.D.
  • 年度 2014
  • 頁碼 155 p.
  • 總頁數(shù) 155
  • 原文格式 PDF
  • 正文語種 eng
  • 中圖分類 遙感技術(shù);
  • 關(guān)鍵詞

相似文獻(xiàn)

  • 外文文獻(xiàn)
  • 中文文獻(xiàn)
  • 專利
獲取原文

客服郵箱：kefu@zhangqiaokeyan.com

京公網(wǎng)安備：11010802029741號 ICP備案號：京ICP備15016152號-6 六維聯(lián)合信息科技 (北京) 有限公司?版權(quán)所有

  • 客服微信

  • 服務(wù)號