本文關(guān)鍵詞：層狀過渡金屬硫族化合物壓應(yīng)力效應(yīng)研究　出處：《中國(guó)科學(xué)技術(shù)大學(xué)》2017年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 過渡金屬硫族化合物 11相鐵基超導(dǎo)體 高壓物理 壓應(yīng)力效應(yīng) 元素替代效應(yīng)

【摘要】：層狀過渡金屬硫族化合物(MXn,M為過渡金屬元素;X = S,Se,Te)材料具有很多新奇的物理性質(zhì),成為近些年凝聚態(tài)物理領(lǐng)域的研究熱點(diǎn),例如,"11"相鐵基超導(dǎo)體FeSe體系、以及光電半導(dǎo)體材料MX2(M = Mo,W;X= S,Se)體系等。在鐵基超導(dǎo)體中,FeSe的結(jié)構(gòu)和組分最為簡(jiǎn)單,常壓下FeSe的超導(dǎo)臨界溫度Tc僅有9 K左右,但Tc靈敏于結(jié)構(gòu)和微結(jié)構(gòu)的變化,在高壓、或單層薄膜體系中超導(dǎo)轉(zhuǎn)變溫度Tc可以提高到37 K和100 K以上。與FeSe不同,MX2是一種具有層狀六方結(jié)構(gòu)的半導(dǎo)體材料,在光電子學(xué)領(lǐng)域中具有廣闊的應(yīng)用前景,該體系的光電性能、能帶結(jié)構(gòu)也靈敏地依賴于結(jié)構(gòu)和微結(jié)構(gòu)性質(zhì)。壓力是調(diào)節(jié)凝聚態(tài)體系結(jié)構(gòu)和微結(jié)構(gòu)的有效手段,通過研究外加壓力、薄膜襯底壓應(yīng)力效應(yīng)、元素替代產(chǎn)生的化學(xué)壓等因素對(duì)材料結(jié)構(gòu)、磁性、電學(xué)性質(zhì)等的影響,可以揭示很多深層次的物理本源。本論文以"11"鐵基超導(dǎo)體FeSe、母體FeTe、以及光電半導(dǎo)體材料WSe2為研究對(duì)象,研究了襯底壓應(yīng)力對(duì)FeSe薄單晶樣品超導(dǎo)電性的調(diào)控;FeTe中Sb元素替代效應(yīng)對(duì)電輸運(yùn)性質(zhì)等的影響;外加壓力對(duì)WSe2的結(jié)構(gòu)和電學(xué)性質(zhì)的調(diào)控。本論文共分為五章:第一章,概述了 "11"相鐵基超導(dǎo)體Fe(Te,Se)體系以及半導(dǎo)體過渡金屬二硫化物MX2(M = Mo,W;X = S,Se)的研究背景以及研究現(xiàn)狀。第二章,雙軸壓應(yīng)力對(duì)FeSe超導(dǎo)電性的增強(qiáng)效應(yīng)。我們制備了高質(zhì)量的FeSe單晶,通過商用膠帶剝離塊材FeSe單晶的方法獲得厚度約幾百納米的薄單晶樣品。研究表明,在該壓應(yīng)力作用下,超導(dǎo)臨界溫度Tc比塊材樣品的9K提升了 30%-40%,上臨界磁場(chǎng)Hc2比塊材樣品的≈14.8 T提高了～20%;同時(shí),表征自旋漲落增強(qiáng)的特征溫度從69 K提高到87 K,然而,結(jié)構(gòu)相變/電子向列相變溫度94K在壓應(yīng)力作用下降低了～5 K。我們的結(jié)果給出了 FeSe中超導(dǎo)電性、向列有序態(tài)和自旋漲落等在壓應(yīng)力下的演化過程,為研究三者之間內(nèi)在關(guān)聯(lián)提供了依據(jù)。第三章,FeTe中Te位替代效應(yīng)對(duì)結(jié)構(gòu)、輸運(yùn)和磁性的有效調(diào)控。我們成功合成了 FeTe1-xSbx系列單晶樣品,研究了 Sb取代Te所產(chǎn)生的化學(xué)壓力對(duì)FeTe磁性和結(jié)構(gòu)性質(zhì)的影響。研究表明,隨著Sb含量的增加,面內(nèi)晶格常數(shù)a逐漸增加,而面外晶格常數(shù)c逐漸收縮,等效于面外單軸壓力效應(yīng)。電阻率、磁化率及比熱測(cè)量結(jié)果一致表明,隨著Sb含量的增加,體系的反鐵磁/結(jié)構(gòu)轉(zhuǎn)變溫度TN從母體的70 K逐漸降低,表明低溫反鐵磁有序態(tài)被逐漸抑制�；魻栂禂�(shù)測(cè)量表明Sb替代Te引入了空穴載流子,但并未誘導(dǎo)出超導(dǎo)電性,這一點(diǎn)與基于巡游磁性的鐵砷體系中可以通過電子或空穴摻雜誘導(dǎo)超導(dǎo)電性不同。我們的結(jié)果表明,FeTe的磁性更加符合基于超交換相互作用的局域自旋模型。第四章,WSe2中壓力誘導(dǎo)的等結(jié)構(gòu)相變和金屬化。我們?cè)诟哌_(dá)62.8 GPa的壓力條件下系統(tǒng)地研究了層狀光電半導(dǎo)體WSe2結(jié)構(gòu)和電性質(zhì),給出了高壓誘導(dǎo)等結(jié)構(gòu)相變和金屬化的直接實(shí)驗(yàn)證據(jù)。一方面,利用原位高壓同步輻射X射線衍射和拉曼光譜實(shí)驗(yàn)技術(shù),我們發(fā)現(xiàn)在28 GPa左右衍射圖譜明顯展寬并且軸向比c/a出現(xiàn)顯著的扭折,同時(shí)拉曼峰發(fā)生劈裂,這些結(jié)果一致表明WSe2發(fā)生了高壓誘導(dǎo)的等結(jié)構(gòu)相變,此外我們還發(fā)現(xiàn)直到最高壓力低壓和高壓結(jié)構(gòu)相仍然是共存的,進(jìn)一步分析表明該等結(jié)構(gòu)相變是面內(nèi)壓縮和層間滑移共同作用的結(jié)果。另一方面,電輸運(yùn)實(shí)驗(yàn)測(cè)量結(jié)果表明伴隨著等結(jié)構(gòu)相變出現(xiàn)了部分金屬化,隨著壓力繼續(xù)增加該金屬化在1.8-300 K的范圍內(nèi)變得越來(lái)越占主導(dǎo),但由于兩相共存直到最高壓力金屬化仍未徹底完成。第五章,總結(jié)與展望。
[Abstract]:Layered transition metal chalcogenides (MXn, M transition metal elements; X = S, Se, Te) materials have many novel physical properties, become the hot research field in recent years condensed state physics, for example, the "11" phase iron based superconductor FeSe system, and the photoelectric semiconductor material MX2 (M = Mo W, X= S, Se); system. In iron-based superconductors, the structure and component of FeSe is the most simple, the superconducting critical temperature Tc under atmospheric pressure FeSe only about 9 K, but the changes in Tc sensitive structure and micro structure under high pressure or thin film system in superconducting transition temperature Tc can be increased to more than 37 K and 100 K. Unlike FeSe, MX2 is a semiconductor material with a layered structure of the six party, and has broad application prospects in the fields of Optoelectronics and optoelectronic properties of the system, the band structure is sensitive to the structure and properties of micro structure. The pressure regulation is condensed the system structure and the micro Effective means of structure, the external pressure through research, thin film substrate stress magnetic effect, chemical pressure and other factors of element substitution on the structure of the material, and the influence of electrical properties, can reveal the physical origin of many deep level. This thesis takes "11" iron based superconductor FeSe, matrix FeTe and photoelectric semiconductor WSe2 material as the research object, to study the substrate stress regulation of FeSe thin single crystal samples of superconductivity; effects of Sb elements in the FeTe substitution effect on electrical transport properties; external pressure regulating structure and electrical properties of WSe2. This paper is divided into five chapters: the first chapter outlines "11" iron based superconductor Fe (Te, Se) and transition metal sulfide semiconductor system two MX2 (M = Mo, W; X = S, Se) the research background and research status. The second chapter, biaxial compressive stress on the enhancement effect of FeSe superconductivity. We prepared the high quality the FeSe single Get a thin crystal, single crystal samples with thickness of about several hundred nanometers by tape stripping method for commercial FeSe bulk single crystal. The results show that the compressive stress, the superconducting critical temperature of Tc increased 30%-40% than the bulk samples of 9K, the upper critical field Hc2 increased to more than 20% in bulk samples is 14.8 T; at the same time, the characteristics of characterization of the spin fluctuation enhanced temperature increased from 69 K to 87 K, however, structural transition / electronic nematic phase transition temperature of 94K in compressive stress was reduced to 5 K. our results are given FeSe super conductivity, to the evolution of ordered state and the spin fluctuations in pressure stress, provide according to the internal relationship between the three. The third chapter is the research of FeTe Te, a substitution effect on the structure, effective regulation and control of transport and magnetism. We successfully synthesized the FeTe1-xSbx series of single crystal samples, the effects of substituting Sb chemical pressure generated by Te on FeTe magnetic Effect and structural properties. The results show that with the increase of Sb content, the in-plane lattice constant a increases gradually, and the out of plane lattice constant of C gradually shrink, equivalent to the surface effect of uniaxial stress. The resistivity, magnetic susceptibility and specific heat measurements. The results showed that with the increase of Sb content, the anti ferromagnetic / system structure transition temperature TN from the maternal 70 K decreased gradually, indicating that low temperature antiferromagnetic ordering is gradually suppressed. Holzer coefficient measurements show that the substitution of Sb Te into the hole, but did not induce superconductivity, and this system based on the magnetic iron arsenic parade may be doped with electron or hole induced superconductivity different. Our results show that FeTe is more consistent with the magnetic superexchange interaction model based on local spin. In the fourth chapter, such as structural transformation and metal induced stress in WSe2. We at pressure up to 62.8 GPa under the condition of Systematic study of the layered structure and electrical properties of WSe2 semiconductor optoelectronics, provides direct experimental evidence for pressure induced structure phase transition and metallization. On the one hand, using in-situ high-pressure synchrotron radiation X ray diffraction and Raman spectroscopy experimental techniques, we found that around 28 GPa diffraction spectrum is broadened significantly and axial ratio c/a kink significantly at the same time, the Raman peaks split, these results show the occurrence of pressure induced structure transition of WSe2, we also found that the highest pressure until the low and high pressure phase structure is still coexist, further analysis shows that the structure transformation is the in-plane compression and interlaminar slip together. On the other hand electrical transport, experimental results show that with the other part of the structural transition metal, with pressure continued to increase the metal in the range of 1.8-300 K becoming increasingly dominant Guide, but due to the coexistence of two phases until the maximum pressure metallization is still not completely completed. The fifth chapter, summary and prospect.

【學(xué)位授予單位】：中國(guó)科學(xué)技術(shù)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：O511.3

【相似文獻(xiàn)】

相關(guān)期刊論文 前6條

1 宋勝年,張其瑞,焦正寬;計(jì)及應(yīng)力效應(yīng)的超導(dǎo)復(fù)合帶的動(dòng)態(tài)穩(wěn)定性[J];低溫物理;1982年03期

2 羅陽(yáng),王振琴;晶粒取向3%Si-Fe疇結(jié)構(gòu)的應(yīng)力效應(yīng)——Ⅰ.張力對(duì)疇結(jié)構(gòu)的影響[J];金屬學(xué)報(bào);1983年02期

3 羅陽(yáng),王振琴;晶粒取向3%Si-Fe疇結(jié)構(gòu)的應(yīng)力效應(yīng)——Ⅱ.壓應(yīng)力對(duì)疇結(jié)構(gòu)的影響[J];金屬學(xué)報(bào);1983年03期

4 傅敏毅,潘國(guó)衛(wèi),焦正寬,丁立人,張勇,陳治友,韓漢民,陳敬林;Cu-Ni包套MgB_2帶應(yīng)力效應(yīng)研究[J];低溫物理學(xué)報(bào);2004年01期

5 李曉蒞,陳唏,劉繼周,陳辰嘉,王學(xué)忠,凌震,王迅,呂少哲;Ⅱ-Ⅵ族稀磁半導(dǎo)體ZnSe/Zn_(1-x)Mn_xSe超晶格中的應(yīng)力效應(yīng)[J];光譜學(xué)與光譜分析;1997年02期

6 羅戰(zhàn)友;杜時(shí)貴;黃曼;;巖石結(jié)構(gòu)面峰值摩擦角應(yīng)力效應(yīng)試驗(yàn)研究[J];巖石力學(xué)與工程學(xué)報(bào);2014年06期

相關(guān)會(huì)議論文 前1條

1 吳光;王貴清;;斜坡巖體環(huán)境應(yīng)力效應(yīng)和環(huán)境剛度效應(yīng)力學(xué)試驗(yàn)研究[A];四川省巖石力學(xué)與工程學(xué)會(huì)首屆學(xué)術(shù)會(huì)議論文集[C];1994年

相關(guān)博士學(xué)位論文 前3條

1 王雪霏;層狀過渡金屬硫族化合物壓應(yīng)力效應(yīng)研究[D];中國(guó)科學(xué)技術(shù)大學(xué);2017年

2 丁建文;低維納米結(jié)構(gòu)體系的電性質(zhì)和應(yīng)力效應(yīng)[D];湘潭大學(xué);2003年

3 白剛;一些功能納米系統(tǒng)尺寸和應(yīng)力效應(yīng)的熱力學(xué)研究[D];南京大學(xué);2013年

，

本文編號(hào)：1397580