本文主要研究内容
作者高庭庭（2019）在《铁基多铁性陶瓷和薄膜的结构与性能》一文中研究指出：由于其丰富的物理内涵及其在自旋电子技术中的巨大应用前景、铁磁/铁电共存并具备磁电耦合效应的多铁性材料正受到广泛的研究关注。本论文工作,系统研究了 Ba4Pr2Fe2Nb8O30陶瓷、La1-xYxFe03陶瓷、SmFe03陶瓷和薄膜等铁基多铁性材料的结构与性能,获得如下主要结论。Ba4Pr2Fe2Nb8030陶瓷具有典型的介电弛豫行为,其宽化的介电常数和介电损耗峰伴随有强烈的频率色散。N2气氛热处理后,介电常数和介电损耗峰值温度显著升高,频率色散行为也明显增强。与之相反,O2气氛热处理会使介电常数和介电损耗峰值温度降低并抑制其频率色散。这些行为都与Fe元素和Pr元素的价态密切相关。晶粒内部的Fe2+和Fe3+之间的跃迁是空气中烧结和N2气氛热处理样品中介电弛豫的起源。室温附近,N2气氛热处理后铁电性的增强是由于Pr4+含量的增加而引起的A1位和A2位离子半径差的增加。同时,陶瓷中存在本征的室温弱铁磁性。在Ba4Pr2Fe2Nb8030陶瓷中实现了近室温的且可被热处理条件所调控的多铁性。在钙钛矿型La1-xYxFeO3陶瓷(x=0,0.25,0.5,0.75,1.0)中,x=0.5的组分Pbnm和P21nm两相共存,其他组分都具有单相Pbnm结构。La0.5Y0.5Fe03陶瓷具有La/Y离子部分岩盐层有序,这种有序方式会产生极性P21nm结构,这与一种特殊形式的非本征铁电性相符合。室温下在La0.5Y0.5FeO3陶瓷中测得了饱和的电滞回线,剩余极化强度为0.11 μμC/cm2,并具有由反铁磁主导而产生的弱铁磁性,由多铁性相P21nm产生的磁电耦合系数达到0.38 mV/cm Oe。这表明La0.5Y0.5FeO3陶瓷可望称为一种新型的室温多铁性材料。在La1-xYxFe03陶瓷中,通过Y离子置换可以调节其介电常数在3个数量级之间变化。两个介电异常分别由低温段直流电导率增加和高温段半导体-金属相变所引起。高温直流电导率机制为二价氧空位的长程移动。随着Y置换量的增加,由于Fe-O-Fe键角的减小,陶瓷的反铁磁相变温度从742 K逐渐降为642 K。磁滞回线和MFM图像都表明了陶瓷中存在弱铁磁性,且磁性随着Y置换量增加而增强。在SmFe03陶瓷和薄膜中都实现了室温多铁性,但其多铁性机制并不一致,陶瓷中具有约0.07 μC/cm2的铁电极化,这比单晶中报道的极化值大一个数量级,起源于不同的铁电机制,SmFeO3陶瓷中的铁电性应该源于Pbn21极性相与Pbnm非极性相的共存。而薄膜中铁电极化达到了约1.5 μC/cm2,这是由于外延结构畸变所引起。而陶瓷和薄膜中均具有由反铁磁Γ2自旋结构引起的弱铁磁性。SmFe03陶瓷中晶界效应是其介电弛豫的主要原因。通过压电力显微镜在CaTi03/SmFe03外延薄膜中观察到了可18 0°翻转的纳米铁电畴,有效压电系数d33约为2 5.1 p m/V。由介电异常获得的铁电相变温度约为306 K,自旋重取向温度约为480 K。由于强的铁电性和弱铁磁性的共存使得材料具有强的磁电耦合作用,磁电系数约为87.6 mV cm-1 Oe-1。
Abstract
you yu ji feng fu de wu li nei han ji ji zai zi xuan dian zi ji shu zhong de ju da ying yong qian jing 、tie ci /tie dian gong cun bing ju bei ci dian ou ge xiao ying de duo tie xing cai liao zheng shou dao an fan de yan jiu guan zhu 。ben lun wen gong zuo ,ji tong yan jiu le Ba4Pr2Fe2Nb8O30tao ci 、La1-xYxFe03tao ci 、SmFe03tao ci he bao mo deng tie ji duo tie xing cai liao de jie gou yu xing neng ,huo de ru xia zhu yao jie lun 。Ba4Pr2Fe2Nb8030tao ci ju you dian xing de jie dian chi yu hang wei ,ji kuan hua de jie dian chang shu he jie dian sun hao feng ban sui you jiang lie de pin lv se san 。N2qi fen re chu li hou ,jie dian chang shu he jie dian sun hao feng zhi wen du xian zhe sheng gao ,pin lv se san hang wei ye ming xian zeng jiang 。yu zhi xiang fan ,O2qi fen re chu li hui shi jie dian chang shu he jie dian sun hao feng zhi wen du jiang di bing yi zhi ji pin lv se san 。zhe xie hang wei dou yu Feyuan su he Pryuan su de jia tai mi qie xiang guan 。jing li nei bu de Fe2+he Fe3+zhi jian de yue qian shi kong qi zhong shao jie he N2qi fen re chu li yang pin zhong jie dian chi yu de qi yuan 。shi wen fu jin ,N2qi fen re chu li hou tie dian xing de zeng jiang shi you yu Pr4+han liang de zeng jia er yin qi de A1wei he A2wei li zi ban jing cha de zeng jia 。tong shi ,tao ci zhong cun zai ben zheng de shi wen ruo tie ci xing 。zai Ba4Pr2Fe2Nb8030tao ci zhong shi xian le jin shi wen de ju ke bei re chu li tiao jian suo diao kong de duo tie xing 。zai gai tai kuang xing La1-xYxFeO3tao ci (x=0,0.25,0.5,0.75,1.0)zhong ,x=0.5de zu fen Pbnmhe P21nmliang xiang gong cun ,ji ta zu fen dou ju you chan xiang Pbnmjie gou 。La0.5Y0.5Fe03tao ci ju you La/Yli zi bu fen yan yan ceng you xu ,zhe chong you xu fang shi hui chan sheng ji xing P21nmjie gou ,zhe yu yi chong te shu xing shi de fei ben zheng tie dian xing xiang fu ge 。shi wen xia zai La0.5Y0.5FeO3tao ci zhong ce de le bao he de dian zhi hui xian ,sheng yu ji hua jiang du wei 0.11 μμC/cm2,bing ju you you fan tie ci zhu dao er chan sheng de ruo tie ci xing ,you duo tie xing xiang P21nmchan sheng de ci dian ou ge ji shu da dao 0.38 mV/cm Oe。zhe biao ming La0.5Y0.5FeO3tao ci ke wang chen wei yi chong xin xing de shi wen duo tie xing cai liao 。zai La1-xYxFe03tao ci zhong ,tong guo Yli zi zhi huan ke yi diao jie ji jie dian chang shu zai 3ge shu liang ji zhi jian bian hua 。liang ge jie dian yi chang fen bie you di wen duan zhi liu dian dao lv zeng jia he gao wen duan ban dao ti -jin shu xiang bian suo yin qi 。gao wen zhi liu dian dao lv ji zhi wei er jia yang kong wei de chang cheng yi dong 。sui zhao Yzhi huan liang de zeng jia ,you yu Fe-O-Fejian jiao de jian xiao ,tao ci de fan tie ci xiang bian wen du cong 742 Kzhu jian jiang wei 642 K。ci zhi hui xian he MFMtu xiang dou biao ming le tao ci zhong cun zai ruo tie ci xing ,ju ci xing sui zhao Yzhi huan liang zeng jia er zeng jiang 。zai SmFe03tao ci he bao mo zhong dou shi xian le shi wen duo tie xing ,dan ji duo tie xing ji zhi bing bu yi zhi ,tao ci zhong ju you yao 0.07 μC/cm2de tie dian ji hua ,zhe bi chan jing zhong bao dao de ji hua zhi da yi ge shu liang ji ,qi yuan yu bu tong de tie dian ji zhi ,SmFeO3tao ci zhong de tie dian xing ying gai yuan yu Pbn21ji xing xiang yu Pbnmfei ji xing xiang de gong cun 。er bao mo zhong tie dian ji hua da dao le yao 1.5 μC/cm2,zhe shi you yu wai yan jie gou ji bian suo yin qi 。er tao ci he bao mo zhong jun ju you you fan tie ci Γ2zi xuan jie gou yin qi de ruo tie ci xing 。SmFe03tao ci zhong jing jie xiao ying shi ji jie dian chi yu de zhu yao yuan yin 。tong guo ya dian li xian wei jing zai CaTi03/SmFe03wai yan bao mo zhong guan cha dao le ke 18 0°fan zhuai de na mi tie dian chou ,you xiao ya dian ji shu d33yao wei 2 5.1 p m/V。you jie dian yi chang huo de de tie dian xiang bian wen du yao wei 306 K,zi xuan chong qu xiang wen du yao wei 480 K。you yu jiang de tie dian xing he ruo tie ci xing de gong cun shi de cai liao ju you jiang de ci dian ou ge zuo yong ,ci dian ji shu yao wei 87.6 mV cm-1 Oe-1。
论文参考文献
论文详细介绍
论文作者分别是来自浙江大学的高庭庭，发表于刊物浙江大学2019-07-04论文，是一篇关于铁电性论文,弱铁磁性论文,多铁性论文,陶瓷论文,薄膜论文,浙江大学2019-07-04论文的文章。本文可供学术参考使用，各位学者可以免费参考阅读下载，文章观点不代表本站观点，资料来自浙江大学2019-07-04论文网站，若本站收录的文献无意侵犯了您的著作版权，请联系我们删除。