Magnetic and dielectric study of R0.5Sr0.5MnO3 (R = Gd, Tb and Dy)
Magnetic and dielectric study of R0.5Sr0.5MnO3 (R = Gd, Tb and Dy)
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DOI：
10.1016/j.materresbull.2010.07.024
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发表时间：
2010-11
影响因子：
5.4
通讯作者：
K. Yoshii;Yusuke Hiramitsu;Y. Okajima;Y. Yoneda;Y. Nishihata;J. Mizuki;A. Nakamura;Y. Shimojo;Y. Ishii;Y. Morii;N. Ikeda
中科院分区：
文献类型：
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作者：
K. Yoshii;Yusuke Hiramitsu;Y. Okajima;Y. Yoneda;Y. Nishihata;J. Mizuki;A. Nakamura;Y. Shimojo;Y. Ishii;Y. Morii;N. Ikeda
研究了钙钛矿型锰矿R0.5Sr0.5MnO3（R=Gd， Tb和Dy）的磁性和介电性能。直流和交流磁测量在Tg ~ 40K时显示出短范围的玻璃状磁有序。这种有序现象是由中子衍射观察到的，这是由于R3+和Sr3+在同一晶体位置随机沉降的尺寸不匹配。每种材料的介电常数在~ 50 ~ ~ 300K之间为~ 1000 ~ 10000，并在Tg以上显示出广泛的最大值。电介质色散表现出极区运动的差相干性，可能是由于尺寸不匹配效应；该体系的磁性和介电性质均受R/Sr位点的随机性支配。tanδ和EXAFS数据表明，介电响应的根源是Mn-3d电子的转移。
Magnetic and dielectric properties of perovskite manganites R0.5Sr0.5MnO3(R=Gd, Tb and Dy) have been investigated. DC and AC magnetic measurements showed short-range glassy magnetic ordering at Tg∼40K. Such ordering was observed by neutron diffraction and is ascribable to the size mismatch of R3+and Sr3+settled randomly at the same crystallographic site. Dielectric constants for each material were ∼1000–10,000 between ∼50 and ∼300K and showed broad maximums above Tg. Dielectric dispersion showed poor coherency of the motion of polar regions, plausibly because of the size-mismatch effect; both the magnetic and dielectric properties of this system are governed by the randomness at the R/Sr site. The tanδ and EXAFS data suggest that the dielectric response is rooted in a transfer of the Mn-3d electrons.