用固相反应法制备了Pr0.4Ca0.6Mn1-xCrxO3(x=0,0.04,0.06,0.08,0.10,0.12),通过X射线衍射(XRD)图谱,磁化强度-温度(M-T)曲线、电子自旋共振(ESR)图谱,并用ESR作出归一化强度-温度(I/I300-T)曲线、谱线宽度-温度(△Bpp-T)曲线,研究Cr3+替代Mn3+对Pr0.4Ca0.6MnO3的磁性质及电荷有序相的影响.结果表明,母体样品Pr0.4Ca0.6Mn03的电荷有序转变温度Tco=267 K,205K~62 K温区是长程反铁磁序,50 K以下在反铁磁背景下出现少量铁磁成分;Cr替代量x=0.06时,电荷有序相已基本被破坏,随温度降低材料从顺磁向反铁磁转变,同时在反铁磁背底下存在铁成分;Cr替代量达到x=0.10时,电荷有序相完全被破坏,250 K以下是反铁磁与铁磁混合相,铁磁成分增多.用有磁性的且与Mn4+有相同电子结构(t2g3eg0)的Cr3+替代Mn3+破坏电荷有序相的机制是:Cr3+替代MR3+引起自旋序的改变从而引起电荷序的破坏,说明在CE型反铁磁体系中,自旋序与电荷序之间存在强耦合相互作用.
参考文献
[1] | 张汝贞,刘宜华,王成建,黄宝歆,季刚,梅良模.Magnetic and Transport Properties of La0.5-xNdxBa0.5CoO3 Compounds[J].稀土学报(英文版),2003(05):558-562. |
[2] | 王桂英,唐永刚,严国清,刘鹏,李莉,彭振生.非化学计量(La0.6Dy0.1Sr0.3)1-xMnO3的电输运及MR温度稳定性机制研究[J].稀土,2013(04):25-29. |
[3] | 王闻琦,王桂英,唐永刚,毛强,刘鹏,彭振生.CuO复合对La0.80Sr0.05K0.15MnO3电输运和磁电阻的影响[J].稀土,2013(03):64-68. |
[4] | 李莉,王桂英,毛强,刘宁,彭振生.La0.80 Sr0.05 Na0.15 MnO3/xCuO复合体电输运机制及磁电阻的温度稳定性[J].稀土,2014(03):82-86. |
[5] | Damay F.;Martin C.;Raveau B.;Maignan A. .MN SITE DOPING INDUCED INSULATOR TO METAL TRANSITION IN PR0.6CA0.4MNO3[J].Journal of Applied Physics,1997(3):1485-1487. |
[6] | Run-Wei Li;Ji-Rong Sun;Zhi-Hong Wang .Effects of the relative proportion of ferromagnetic and charge-ordered phases on the metal-insulator transition temperature in La_(0.5)Ca_(0.5)Mn_(1-x)Ge_(x)O_(3)[J].Journal of Applied Physics,2000(12):7041-7044. |
[7] | 彭振生,宋启祥,杨刚,王桂英,唐永刚,毛强.Cr3+或V3+替代Mn3+对La0.4Ca0.6MnO3电荷有序相的影响[J].稀有金属,2012(01):74-79. |
[8] | Damay F.;Maignan A.;Hervieu M.;Raveau B.;Bouree F.;Andre G.;Martin C. .Neutron diffraction evidence for a new ferromagnetic phase in Cr doped Pr0.5Ca0.5MnO3[J].Applied physics letters,1998(25):3772-3774. |
[9] | 赫文秀,安胜利,张永强,王亚雄,张金超.改进固相法制备钙钛矿结构La1-x Srx Ga1-y Mgy O3-δ及其性质研究[J].稀土,2011(05):1-5. |
[10] | Y. Tomioka;T. Okuda;Y. Okimoto .Charge/orbital ordering in perovskite manganites[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2001(1/2):27-35. |
[11] | Kuwahara H;Tomioka Y;Asamitsu A;Moritomo Y;Tokura Y .A FIRST-ORDER PHASE TRANSITION INDUCED BY A MAGNETIC FIELD[J].Science,1995(5238):961-963. |
[12] | 洪波 .钙钛矿锰氧化物的电荷序、轨道序、自旋序及其相互作用[D].中国科学技术大学,2007. |
[13] | 童伟 .钴基和锰基钙钛矿氧化物的磁性和输运性研究[D].中国科学技术大学,2004. |
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