Low-field magnetoelectric effect at room temperature
Low-field magnetoelectric effect at room temperature
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DOI：
10.1038/nmat2826
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发表时间：
2010-10-01
期刊：
影响因子：
41.2
通讯作者：
Kimura, Tsuyoshi
中科院分区：
文献类型：
--
作者：
Kitagawa, Yutaro;Hiraoka, Yuji;Kimura, Tsuyoshi
BiFeO_3中巨大铁电极化的发现（参考文献1）和TbMnO_3中伴随磁序的铁电性的发现（参考文献2）从基础和技术的观点（5-7）重新引起了人们对磁电多铁性材料（3，4）的研究兴趣。磁电多铁性材料是磁性和铁电性有序共存的材料。在几种不同类型的磁电多铁性（8，9）中，磁感应铁电体（其中铁电性是由复杂的磁序（例如螺旋序）引起的）表现出巨磁电效应，即响应于磁场的电极化的显著变化。在过去的几年里，已经发现了许多显示磁电效应的磁感应铁电体（10）。然而，从实用的角度来看，它们的磁电效应是无用的，因为它们只能在远低于室温的温度下工作（例如，TbMnO 3中为28 K（参考文献2），CuO中为230 K（参考文献11））。此外，在大多数情况下，工作磁场是特斯拉的数量级，这对于实际应用来说太高了。在这里，我们报告的材料，Z型六角铁氧体，克服这些问题的磁感应铁电体。在氧气氛中烧结的Sr 3Co 2Fe 24 O 41陶瓷具有最好的磁电性能，在室温下表现出低场磁电效应。我们的结果代表了一个重要的一步，实际设备的应用，使用磁电效应。
The discoveries of gigantic ferroelectric polarizaion in BiFeO3 (ref. 1) and ferroelectricity accompanied by a magnetic order in TbMnO3 (ref. 2) have renewed interest in research on magnetoelectric multiferroics(3,4), materials in which magnetic and ferroelectric orders coexist, from both fundamental and technological points of view(5-7). Among several different types of magnetoelectric multiferroic(8,9), magnetically induced ferroelectrics in which ferroelectricity is induced by complex magnetic orders, such as spiral orders, exhibit giant magnetoelectric effects, remarkable changes in electric polarization in response to a magnetic field. Many magnetically induced ferroelectrics showing the magnetoelectric effects have been found in the past several years(10). From a practical point of view, however, their magnetoelectric effects are useless because they operate only far below room temperature (for example, 28 K in TbMnO3 (ref. 2) and 230 K in CuO (ref. 11)). Furthermore, in most of them, the operating magnetic field is an order of tesla that is too high for practical applications. Here we report materials, Z-type hexaferrites, overcoming these problems on magnetically induced ferroelectrics. The best magnetoelectric properties were obtained for Sr3Co2Fe24O41 ceramics sintered in oxygen, which exhibit a low-field magnetoelectric effect at room temperature. Our result represents an important step towards practical device applications using the magnetoelectric effects.