1] Department of Physical Chemistry, University of Science and Technology Beijing, Beijing 100083, China [2] State Key Laboratory for Advanced Metallurgy, University of Science and Technology Beijing, Beijing 100083, China.
Sci Rep. 2013;3:2458. doi: 10.1038/srep02458.
Control of negative thermal expansion is a fundamentally interesting topic in the negative thermal expansion materials in order for the future applications. However, it is a challenge to control the negative thermal expansion in individual pure materials over a large scale. Here, we report an effective way to control the coefficient of thermal expansion from a giant negative to a near zero thermal expansion by means of adjusting the spontaneous volume ferroelectrostriction (SVFS) in the system of PbTiO3-(Bi,La)FeO3 ferroelectrics. The adjustable range of thermal expansion contains most negative thermal expansion materials. The abnormal property of negative or zero thermal expansion previously observed in ferroelectrics is well understood according to the present new concept of spontaneous volume ferroelectrostriction. The present studies could be useful to control of thermal expansion of ferroelectrics, and could be extended to multiferroic materials whose properties of both ferroelectricity and magnetism are coupled with thermal expansion.
控制负热膨胀是负热膨胀材料未来应用中一个非常有趣的课题。然而，要在较大范围内控制单个纯材料的负热膨胀是一个挑战。在这里，我们报告了一种通过调整 PbTiO3-(Bi,La)FeO3 铁电体系统中的自发体积铁电伸缩（SVFS）来控制热膨胀系数从巨大的负膨胀到接近零膨胀的有效方法。热膨胀的可调范围包含了大多数负热膨胀材料。根据自发体积铁电伸缩的新概念，目前可以很好地理解铁电体中以前观察到的负或零热膨胀的异常性质。本研究对于控制铁电体的热膨胀是有用的，并可扩展到磁电性能与热膨胀相关的多铁材料。
