Negative permittivity behavior and magnetic performance of perovskite La1−xSrxMnO3 at high-frequency
Negative permittivity behavior and magnetic performance of perovskite La1−xSrxMnO3 at high-frequency
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DOI：
10.1039/c3tc31906g
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发表时间：
2014-01
影响因子：
6.4
通讯作者：
K. Yan;R. Fan;Zhicheng Shi;Min Chen;Lei Qian;Yulei Wei;Kai Sun;Jing Li
中科院分区：
文献类型：
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作者：
K. Yan;R. Fan;Zhicheng Shi;Min Chen;Lei Qian;Yulei Wei;Kai Sun;Jing Li
对于双负材料（DNM），这些通常在人工超材料或一些金属/陶瓷复合材料中观察到。在这里，发现了单相钙钛矿La 1 − xSrxMnO 3（LSMO）的有趣的负介电常数行为。通过溶胶-凝胶/烧结工艺制备了x值为0.2或0.5的LSMO块体。从微观结构上看，块体几乎为单相，主相为钙钛矿结构，同时，块体具有较高的致密度。此外，等离子体类负介电常数的实验数据与有耗Drude模型拟合良好，表明等离子体频率为3.85 GHz（x = 0.5）。LSMO的复磁导率在0.2 ~ 1GHz（x = 0.2）和0.6 ~ 1GHz（x = 0.5）频率范围内呈现负磁化率（μ′ < 1）。这些结果对于实现单相LSMO的双负性质具有重要意义，LSMO是一种有前途的DNM候选者。
For double negative materials (DNMs), these are usually observed in artificial metamaterials or some metal/ceramic composites. Here, an interesting negative permittivity behavior of single-phase perovskite La1−xSrxMnO3 (LSMO) is found. The LSMO bulks with an x value of 0.2 or 0.5 were prepared by a sol–gel/sintering process. From microstructure characterization, the bulks are nearly in single phase and the major phase belongs to the perovskite structure; meanwhile, the bulks are of high density. Furthermore, the experimental data of the plasma-like negative permittivity are fitted well by a lossy Drude model, suggesting a plasma frequency of 3.85 GHz (x = 0.5). The complex permeability of LSMO presents a negative susceptibility (μ′ < 1) at a frequency range of 0.2–1 GHz (x = 0.2) and 0.6–1 GHz (x = 0.5). These results have important implications for the realization of double negative properties in single-phase LSMO as a promising candidate for DNMs.