The Mn-doping effect on the charge ordering state of La1/3Sr2/3FeO3
The Mn-doping effect on the charge ordering state of La1/3Sr2/3FeO3
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Mn掺杂对La1/3Sr2/3FeO3电荷有序态的影响
DOI：
10.1016/j.jallcom.2010.09.038
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发表时间：
2011-01
影响因子：
6.2
通讯作者：
Zhu Changfei
中科院分区：
文献类型：
--
作者：
Kong Hui;Kong Zhang-Qing;Zhu Changfei
研究重点：>对于La{sub 1/3}Sr{sub 2/3}Fe{sub 1-x}Mn{sub x}O{sub 3}体系，随着Mn掺杂量的增加，电阻率增大，电荷有序转变温度T{sub CO}向低温偏移。La{sub 1/3}Sr{sub 2/3}Fe{sub 1-x}Mn{sub x}O{sub 3}样品中存在两种晶格畸变。>第一种是由高自旋Fe{sup 4+}的扬-泰勒效应引起的畸变，第二种是呼吸型畸变。Mn的掺杂增强了jhn - teller效应，减弱了呼吸型畸变。摘要：在20 ~ 300 K的10 MHz频率下，测量了单相多晶La{sub 1/3}Sr{sub 2/3}Fe{sub 1-x}Mn{sub x}O{sub 3} （x = 0,0.025, 0.05）的纵向超声速度（V{sub l}）和电阻率。发现随着mn掺杂量的增加，电阻率增大，电荷有序转变温度T{sub CO}向低温偏移。对于所有样品，从300k冷却后，观察到在T{sub CO}以上的V{sub l}中有明显的软化，在T{sub CO}以下有明显的硬化。平均场理论可以很好地描述T{sub CO}以上的异常弹性软化，表明这是由于电子-声子通过Jahn-Teller效应耦合引起的，Mn的掺杂增强了这种耦合。在T{sub CO}以下，当x = 0时，在V{sub l}中出现另一种软化，随着Mn含量的增加而减弱。这一特征归因于Fe-O八面体的呼吸型畸变，表明Mn取代抑制了电荷歧化（CD）转变。
Research highlights: > For La{sub 1/3}Sr{sub 2/3}Fe{sub 1-x}Mn{sub x}O{sub 3} system, with increasing the Mn-doping level, the resistivity increases and the charge ordering transition temperature T{sub CO} shifts to lower temperature. > Two kinds of lattice distortion exist in La{sub 1/3}Sr{sub 2/3}Fe{sub 1-x}Mn{sub x}O{sub 3} samples. > The first is the distortion arising from the Jahn-Teller effect of high-spin Fe{sup 4+}, and the second is the breathing-type distortion. > With the Mn doping, the Jahn-Teller effect is enhanced, and the breathing-type distortion is weakened. - Abstract: The longitudinal ultrasonic velocity (V{sub l}), as well as resistivity has been measured in single-phase polycrystalline La{sub 1/3}Sr{sub 2/3}Fe{sub 1-x}Mn{sub x}O{sub 3} (x = 0, 0.025, 0.05) at a frequency of 10 MHz, from 20 K to 300 K. It is found that with increasing Mn-doping level, the resistivity increases and the charge ordering transition temperature T{sub CO} shifts to lower temperature. For all samples, upon cooling down from 300 K, a substantial softening in V{sub l} above T{sub CO} and dramatic stiffening below T{sub CO} are observed. This abnormal elastic softening above T{sub CO} can be described well by the mean-field theory, which indicates that this feature is due to the electron-phonon coupling via the Jahn-Teller effect and this coupling is enhanced with the Mn doping. Below T{sub CO}, another softening in V{sub l} is observed for x = 0, and weakens with the increasing of Mn content. This character is attributed to the breathing-type distortion of Fe-O octahedron and suggests that the charge disproportionation (CD) transition is suppressed by the Mn substitution.
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DOI：
10.1103/physrevb.46.1157
发表时间：
1992-07
期刊：
Physical review. B, Condensed matter
影响因子：
--
作者：
M. Cankurtaran;G. A. Saunders;K. Goretta;R. B. Poeppel
通讯作者：
M. Cankurtaran;G. A. Saunders;K. Goretta;R. B. Poeppel
影响因子：
4
作者：
Xiaoguang Li;Houtong Chen;C. Zhu;Haibiao Zhou;R. Zheng;Jiahui Zhang;Luo Chen
通讯作者：
Xiaoguang Li;Houtong Chen;C. Zhu;Haibiao Zhou;R. Zheng;Jiahui Zhang;Luo Chen
影响因子：
3.7
作者：
J. Matsuno;T. Mizokawa;A. Fujimori;K. Mamiya;Y. Takeda;S. Kawasaki;M. Takano
通讯作者：
J. Matsuno;T. Mizokawa;A. Fujimori;K. Mamiya;Y. Takeda;S. Kawasaki;M. Takano
DOI：
10.1088/0953-8984/13/28/304
发表时间：
2001-06
期刊：
Journal of Physics: Condensed Matter
影响因子：
--
作者：
Haidong Zhou;Guanghai Li;Houtong Chen;R. Zheng;X. Fan;Xiaoguang Li
通讯作者：
Haidong Zhou;Guanghai Li;Houtong Chen;R. Zheng;X. Fan;Xiaoguang Li
影响因子：
3.7
作者：
Shankar Ghosh;N. Kamaraju;M. Seto;A. Fujimori;Y. Takeda;S. Ishiwata;S. Kawasaki;M. Azuma;M. Takano;A. Sood
通讯作者：
Shankar Ghosh;N. Kamaraju;M. Seto;A. Fujimori;Y. Takeda;S. Ishiwata;S. Kawasaki;M. Azuma;M. Takano;A. Sood