本文選題：鈣鈦礦錳氧化物　切入點：輸運特性　出處：《蘇州科技大學(xué)》2017年碩士論文

【摘要】：由于電子自旋、電荷、軌道和晶格之間的強關(guān)聯(lián),鈣鈦礦型過渡族金屬氧化物材料呈現(xiàn)出極為豐富的新奇物理現(xiàn)象,如金屬-絕緣體轉(zhuǎn)變、相分離以及超大磁阻效應(yīng)等。錳氧化物各量子態(tài)具有相近的自由能,導(dǎo)致多個亞穩(wěn)態(tài)的競爭與共存,使得錳氧化物對物理場十分的敏感。本論文中,以鈣鈦礦錳氧化物材料La_(0.9)Hf_(0.1)MnO_3(LHMO)作為研究對象,系統(tǒng)地研究其薄膜與異質(zhì)結(jié)在光、電、磁和應(yīng)力場的調(diào)制下的電輸運性質(zhì)。具體內(nèi)容如下:1、采用脈沖激光沉積的制備工藝,在SrTiO_3(001)襯底上制備LHMO薄膜,改變退火氧壓和退火時間,研究退火條件對薄膜電輸運特性的影響。結(jié)果表明提高退火氧壓和延長退火時間都會提高薄膜的金屬絕緣轉(zhuǎn)變溫度。2、研究晶格失配對LHMO薄膜電輸運特性的影響。選用不同晶格常數(shù)的襯底提供不同的應(yīng)力,分別在SrTiO_3(STO),LaAlO_3(LAO),(La Al O_3)_(0.3)(Sr_2AlTaO_6)_(0.7)(LSAT)、KTaO_3(KTO)、和(Zr,Y)O_2(YSZ)單晶襯底上生長LHMO薄膜。研究發(fā)現(xiàn)應(yīng)力會降低薄膜的金屬-絕緣轉(zhuǎn)變溫度,從而影響材料的電輸運特性。3、研究應(yīng)力場與光場共同作用下,LHMO薄膜電輸運特性的變化。在光場的調(diào)控下,薄膜出現(xiàn)光致電阻效應(yīng),并將兩種不同應(yīng)力作用下的光致電阻率進行對比,發(fā)現(xiàn)壓應(yīng)力作用下的光致電阻效應(yīng)較為明顯。4、研究薄膜受磁場調(diào)控的影響時,比較電子導(dǎo)電的薄膜與空穴導(dǎo)電的薄膜的磁輸運特性。在LSAT襯底上分別制備LHMO和La_(0.8)Ba_(0.2)MnO_3(LBMO)薄膜,LHMO薄膜是電子導(dǎo)電型,LBMO薄膜是空穴導(dǎo)電型。結(jié)果發(fā)現(xiàn)無論是電子導(dǎo)電的薄膜還是空穴導(dǎo)電的薄膜,在磁場的調(diào)制下,薄膜的電阻都會隨磁場的增大而變小,并在某一溫度有薄膜的最大龐磁電阻率。5、研究La_(0.9)Hf_(0.1)MnO_3/0.05 wt%Nb-SrTiO_3(NSTO)異質(zhì)結(jié)的性能,包括異質(zhì)結(jié)的整流效應(yīng)和光電效應(yīng)。對異質(zhì)結(jié)進行光、電、磁場的多場調(diào)控,研究整流效應(yīng)的場調(diào)控。結(jié)果表明在多場調(diào)制下,反向電流變大的同時,正向電流也變大,異質(zhì)結(jié)表現(xiàn)出更好的整流特性。
[Abstract]:Due to the strong correlation between electron spin charge orbital and lattice perovskite-type transition metal oxide materials exhibit novel physical phenomena such as metal-insulator transition phase separation and super-large magnetoresistive effect.The quantum states of manganese oxide have similar free energy, which leads to the competition and coexistence of many metastable states, which makes manganese oxide very sensitive to physical field.In this paper, the perovskite manganese oxide material LaCo0.9HfD _ (0.1) MNO _ (3) LHMOs is taken as the research object, and the electrical transport properties of the thin film and heterojunction under the modulation of light, electricity, magnetism and stress field are systematically studied.The specific contents are as follows: 1. LHMO thin films were prepared on SrTiO-1 substrates by pulsed laser deposition. The effects of annealing conditions on the electrical transport properties of the films were studied by changing the annealing oxygen pressure and annealing time.The results show that increasing annealing oxygen pressure and prolonging annealing time can increase the transition temperature of metal insulation. The effect of lattice mismatch on the electrical transport characteristics of LHMO thin films is studied.閫夌敤涓嶅悓鏅舵牸甯告暟鐨勮‖搴曟彁渚涗笉鍚岀殑搴斿姏,鍒嗗埆鍦⊿rTiO_3(STO),LaAlO_3(LAO),(La Al O_3)_(0.3)(Sr_2AlTaO_6)_(0.7)(LSAT),KTaO_3(KTO),鍜，

本文編號：1709325