BTO基多铁陶瓷的制备及物理性能研究  

Preparation and Physical Property of BTO-based Multiferroic Ceramics

作　　者：李胜[1] 宋国强 张媛媛[1] 唐晓东[1] LI Sheng;SONG Guoqiang;ZHANG Yuanyuan;TANG Xiaodong(Key Laboratory of Polar Materials and Devices,Ministry of Education,Department of Electronic Science,East China Normal University,Shanghai 200241,China)

机构地区：[1]华东师范大学电子科学系,极化材料与器件教育部重点实验室,上海200241

出　　处：《无机材料学报》2022年第1期79-85,共7页Journal of Inorganic Materials

基　　金：国家自然科学基金(61674058,61574058)。

摘　　要：多铁材料在新型器件领域的应用非常广泛,其研究已成为当今材料研究领域的热点之一。钛酸钡(BaTiO_(3),BTO)在室温下具有较强的铁电性、高介电常数和电光特性等丰富的物理性能,吸引了科研人员对其进行多铁化的研究。本工作通过固相烧结法制备BTO和BaTi_(0.94)(TM_(1/2)Nb_(1/2))_(0.06)O_(3)(TM=Mn/Ni/Co)陶瓷,系统研究了B位共掺杂对陶瓷的生长特性与电学、磁学和光学方面的影响。实验结果表明:掺杂有效抑制了六方相的产生,样品晶体结构由四方相向立方相转变,不同元素离子半径的差异使得相变的程度有所不同。通过拉曼散射发现BTO基陶瓷四方相的特征峰变弱,进一步证明了共掺杂导致四方相减少。介电温谱表明BaTi_(0.94)(TM_(1/2)Nb_(1/2))_(0.06)O_(3)的居里温度(TC)也较BTO有大幅度降低,同时样品的铁电性虽然也明显削弱,但是还保持有较好的铁电性,这些都和晶体结构的相变程度密切相关。磁性测试结果表明:在三组共掺组分中,Ni-Nb共掺杂具有最好的室温铁磁性,铁磁性的形成机制可以通过F中心交换(F-center exchange,FCE)理论来解释。与BTO相比,BaTi_(0.94)(TM_(1/2)Nb_(1/2))_(0.06)O_(3)的带隙明显减小,这主要是因为掺杂产生杂质能级使带隙减小,与能带理论吻合。上述结果表明:通过B位共掺杂可以获得室温下铁电性与铁磁性共存的BTO基多铁陶瓷,有望在多铁性功能器件中获得更广泛的应用。Multiferroic material is one of hot spots in the materials research area which can be widely used in many new functional devices.Barium titanate(BaTiO_(3),BTO)has attracted many interests for its multiferroic properties,such as ferroelectricity,high dielectric constant and electro-optical properties at room temperature.The BaTi_(0.94)(TM_(1/2)Nb_(1/2))_(0.06)O_(3)(TM=Mn/Ni/Co)ceramic samples were prepared by solid state reaction method,and their structure,electrical,magnetic,and optical properties were systematically studied.The crystal structure of all doped samples changes from tetragonal to cubic phase without any hexagonal phase depending on ionic radius.Weakening of Raman scattering peaks of BTO tetragonal phase further proves the phase transition to cubic phase caused by doping.The Curie temperature(TC)has a dramatic decrease with the dopant as the phase transition from tetragonal phase to cubic phase.Although the ferroelectricity is weakened,it is still existed.The magnetic measurement suggests that Ni-Nb doped sample has the strongest ferromagnetism among different dopants which can be deduced by the F-center exchange(FCE)theory.Furthermore,energy gaps of BaTi_(0.94)(TM_(1/2)Nb_(1/2))_(0.06)O_(3) are obviously reduced compared to that of BTO,which can be reasonably explained by impurity level and band theory.These results indicate that BTO based multiferroic ceramics with ferroelectric and ferromagnetic coexisting at room temperature can be obtained by B-site co-doping,which can be expected to be widely used in multiferroic functional devices.

关 键 词：钛酸钡 铁电性 多铁性 掺杂 

分 类 号：TQ174[化学工程—陶瓷工业]