CoAl2O4/Al2O3納米復合陶瓷的結構與表征

功能材料2004年增刊(35)卷CoAl2O4A2O3納米復合陶瓷的結構與表征張棟杰,王克宇南京師范大學(xué)材料科學(xué)重點(diǎn)實(shí)驗室,江蘇南京21009摘要:利用溶膠-凝膠方法制備了的CoAl2O4Al2O圖譜。納米復合陶瓷,并用Xray分析(XRD)、紅外光譜(IR)和掃描電鏡分析(SEM對其結構進(jìn)行了分析。結果表明隨Al2O3含量增多CoAl2O4尖晶石相從CoAl2O4Al2O3凝膠中的析晶溫度升高。SEM形貌也說(shuō)明,隨Al2O3含量增多,CoAl2O4Al2O3陶瓷中形成一定的層狀結構。關(guān)鍵詞:CoAl2O4;鐵氧體;結構;納米復合中圖分類(lèi)號:O482.54文獻標識碼:A文章編號:1001-9731(2004)增刊2θ1(°)1引言b: Al..鋁酸鈷CoAl2O4為尖晶石結晶的立方晶體。1978年,有人將其用于彩色電視機藍色熒光粉ZnS:Ag的包膜處理大大改善了電視圖像的質(zhì)量。經(jīng)特殊處理的熒光粉CoAl2O4體系還可以改善發(fā)光效率、亮度等指標2。特別是并最近幾年,人們也開(kāi)展了Co-A-O顆粒膜的巨磁電阻隧和多層膜隧道結巨磁電阻等磁性能的廣泛研究;對于陶瓷方面,人們也開(kāi)展了201(°)同類(lèi)尖晶石結構的ZnFe2O4研究。本文研究了CoAl2O4Al2O3納米復合陶瓷的結bAL.o構,為進(jìn)一步研究其巨磁電阻打下基礎2實(shí)驗以分析純Co(NO3)、Al(NO3、檸檬酸、乙醇、聚乙烯醇為起始原料,采用溶膠一凝膠法合成CoA2O4A2O3納米復合陶瓷,考慮鋁組分的變化對納米結構的影響,設計了三種組分CoAl2O4,其中x=0.45、0.20和0.10,分別用1#、2#和3#表示。樣品圖1CoAl2O4Al2O3凝膠在不同熱處理溫度時(shí)的的晶相結構由Dmax-b型ⅹ射線(xiàn)衍射儀測定;形貌譜由JSM-5610LV掃描電鏡觀(guān)測。Fig 1 The XRD curve of CoAl,O4/Al,O3 gel at different3實(shí)驗結果與分析由圖可見(jiàn),1#凝膠在400°C熱處理時(shí)仍為非晶圖1為凝膠在不同熱處理溫度時(shí)的X射線(xiàn)衍射態(tài)在600℃以上時(shí)有晶相析出并且是單相CoAl2O4作者簡(jiǎn)介:張棟杰(19∠通訊作者張棟杰副教授,主要從事鐵電、鐵磁功能材料與器件的研究。收稿日期:2004-05-05男,河南洛陽(yáng)人,博中國煤化工CNMHG張棟杰等:CoA2O納米復合陶瓷的結構與表征274尖晶石。2#凝膠在600°熱處理時(shí)還是非晶態(tài),而1#凝膠在600°時(shí)有CoAl2O4尖晶石結晶,說(shuō)明2#凝膠中較多的Al2O3阻礙了CoAl2O4尖晶石的形成在600~1400%時(shí),CoAl2O4尖晶石是主晶相,但在1400°C有Al2O3結晶。3#凝膠在700°C熱處理時(shí)還是非晶態(tài),而1#凝膠在400°℃C時(shí)和2#凝膠在600°C熱處理時(shí)的非晶態(tài)溫度提高了100-300%,說(shuō)明凝膠中較多的A2O3阻礙了CoAl2O4尖晶石的結晶和晶粒長(cháng)大;在800°℃C時(shí),有單相CoAl2O4尖晶石析出樣在1400°C有Al2O3結晶。圖3在1400°燒結的CoAl2O4A2O3陶瓷的SEM形貌Fig 3 SEM of CoAl2O4Al2O3 ceramics sintered at 1400oC4結論COALO4AlO3凝膠中,隨著(zhù)Al2O3含量的增多CoAl2O尖晶石相的析晶溫度升高,較多的Al2O3阻礙4000了CoAl2O4尖晶石的結晶及其晶粒長(cháng)大;在1400°C有wavenumber/cmAl2O3相結晶。1400°C的SEM形貌也表明,隨著(zhù)A2O3含量的增多,CoAl2O4/AlO3陶瓷中具有層狀結構。參考文獻[1 Miyata Yoshihihiko. The use of coballalum innate pigmenton the ZnS Ag blue phosphor coat [J]. Jpn Kokai TokkyoKoho,l987,78:192] Yoshiyuki N. Coballaluminate effect on the TV's using age[] Jpn Kokai Tokkyo Koho, 1987, 52: 1191#800℃[3]張振剛,黎超,李成賢等,不同襯底溫度下制備CoA-O介質(zhì)顆粒薄膜的巨磁電阻效應[J.蘭州大學(xué)學(xué)報,199935(1):57-61wavenumbericm[4] FujimoriH, MitaniS, Ohnumas. Tunnel-type GMR圖2CoAl2O4Al2O3凝膠在不同溫度的紅外譜Co-Al-O insulated granular system-its oxygen concentrationFig 2 The IR curve of CoAl2O4/Al2O3 gel at differenttemperature5] Ping Sheng, Ables B, Arie Y Hopping conductivity in圖2為凝膠和經(jīng)過(guò)一定溫度處理的樣品紅外光granular metals [J]. Phys Rev Lett, 1973, 31: 44譜。在凝膠樣品中3412cm為HO以及OH基團的[6] Mitani, Fujimori, Numas. Spin-dependent tunnelingphenomena in insulating granular system S [].J Magn吸收峰;1728cm'和1378cm為檸檬酸的羧酸基magn Mater. 1997. 165: 14COCOOH的吸收峰;對于800~900°C處理的樣品[7] Inoue J, Maekawas. Theory of tunneling magnetoresistance820cm、為Al-O基團的吸收峰而670cm和550cm為CoAl2O4的吸收峰。[8]都有為,陳鵬朱建民.納米結構ZnFe3O-a-FeO3多晶材圖3分別為凝膠在1400℃C處理3h的SEM形貌料中的巨隧道磁電阻效應卩.物理學(xué)報,2001,50:2275隨著(zhù)Al2O3含量的增多,從2#和3#有層狀形貌出現(下轉第2748頁(yè))中國煤化工CNMHG功能材料204年增刊(35)卷中棒狀納米材料的可控合成4結論參考文獻采用水溶液/ Triton X100正己醇/環(huán)己烷反相微1倪天增羅冬冬范力仁等納米氧化鉍的制備與應用]中乳液體系,保持 Triton X-100/環(huán)己烷/正己醇的體積比南民族大學(xué)學(xué)報(自然科學(xué)版),200423(1):26-29不變,通過(guò)改變加入的水溶液體積和硝酸鉍的濃度,(2]吳曉春湯國慶不同制備條件對納米BiO3發(fā)光的影響可得到不同水核半徑W0和不同硝酸鉍濃度下的不同化學(xué)學(xué)報,199654:14長(cháng)徑比的棒狀納米氧化鉍前驅體,實(shí)現了在受限空間Micro-emulsion preparation of nanometer-sizedbasic bismuth nitrate stickFAN Li-ren, CAO Qi-gao, NI Tian-zeng, LI Hai-fen(Faculty of Material Science and Chemical Engineering, China University of Geosciences, Wuhan 430074, China)ized basic bismuth nitrate that was confirmed by TEM andsuccessfully using aqua solution/TritonX-100/hexanol/ cyclohexane reversed phase micro-emulsion system. To fairlycopy the stick structure of water-core, it is very important to optimize the experiment conditions especially keepvolume ratio of Triton X-100/hexanol/cyclohexane and control water-core semi-diameter Wo. With changing volumeof water and concentration of bismuth nitrate, several size stick products have been obtained, their length anddiameter were characterized by TEMKey words: nanometer-sized BiONO3 stick micro-emulsion preparation morphologyL上接第2745頁(yè))Structure of CoAl2O4/AlO3 nanocomposition ceramicsZHANG Dong-jie, WANG Ke-yu(Laboratory of Materials Science, Nanjing Normal University, Nanjing 210097, China)Abstract: The CoALO4Al2O, nanocomposition Ceramics were fabricated by sol-gel method with treatment indifferent temperature. The structure was analyzed by XRD, IR and SEM together. The result was that crystallizingtemperature of CoAl2O4 spinel from gel rise, while the layered structure was also formed with Al,O, contentKeywords: CoAl2O4: ferrite; structure: nanocomposition中國煤化工CNMHG