...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Dalton transactions: An international journal of inorganic chemistry >Synthesis, structural, magnetic and phase-transition studies of the ferromagnetic La2CoMnO6 double perovskite by symmetry-adapted modes
【24h】

Synthesis, structural, magnetic and phase-transition studies of the ferromagnetic La2CoMnO6 double perovskite by symmetry-adapted modes

机译：铁磁La2CoMnO6双钙钛矿的对称适应模式合成，结构，磁性和相变研究

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

A powdered La2CoMnO6 double perovskite was synthesized by the solid-state reaction method, and its crystal structure was investigated by (mode-crystallography) Rietveld analysis using X-ray and neutron powder diffraction data. La2CoMnO6 material is a monoclinic perovskite at room temperature, adopting the space group P2(1) (a(-)a(-)b(+)), a approximate to b approximate to root 2a(p), c approximate to 2a(p) and Z = 2. The P2(1) phase can be described effectively by three distortion modes (GM(4)(+), X-3(+), X-5(+)) of the Fm (3) over barm (a(0)a(0)a(0)) parent phase. The comparative study of the material and those in the Ln(2)CoMnO(6) and Ln(2)NiMnO(6) families has shown a general trend in nearly all the materials, has served to select a common direction in the sub-space spanned by X-5(+), tri-linearly coupled to the order parameters of the cubic to monoclinic first order phase transition. This direction has been used to parametrize the refinements and to perform reliable refinements in the high-temperature intermediate distorted trigonal phase, R (3) over bar (a(-)a(-)a(-)), for which only one effectively acting irrep has been deduced: GM(5)(+), physically a tilt of the oxygen sharing octahedra of Co and Mn. Its temperature evolution up to the prototype cubic phase has been fitted in the framework of the Landau Theory of Phase Transitions, showing a behavior typical of a tricritical point. The low-temperature neutron powder diffraction data have served to solve the magnetic structure: three indistinguishable ferromagnetic models with the space groups P2(1) and P2'(1)' are proposed.
机译：通过固相反应法合成了粉末状的La2CoMnO6双钙钛矿，并利用X射线和中子粉末衍射数据通过（模式晶体学）Rietveld分析研究了其晶体结构。 La2CoMnO6材料在室温下为单斜晶钙钛矿，采用空间群P2（1）/ n（a（-）a（-）b（+）），b近似于根2a（p），c近似于2a（p）和Z =2。P2（1）/ n相位可以通过三个失真模式（GM（4）（+），X-3（+），X-5（+））有效地描述。 Fm（3）在barm（a（0）a（0）a（0））父阶段上。对材料以及Ln（2）CoMnO（6）和Ln（2）NiMnO（6）系列中的材料进行的比较研究表明，几乎所有材料都具有总体趋势，有助于在子材料中选择共同的方向。 X-5（+）跨越的空间，三次线性耦合到立方到单斜的一阶相变的阶数参数。此方向已被用于参数化细化，并在棒（a（-）a（-）a（-））上的高温中间扭曲三角相R（3）中执行可靠的细化，对此仅有效可以推断出作用的irrep：GM（5）（+），实际上是Co和Mn的氧共享八面体的倾斜。直到原型立方相的温度演化都已纳入Landau相变理论的框架，显示出三临界点的典型行为。低温中子粉末衍射数据已经解决了磁性结构：提出了三个具有空间群P2（1）/ n和P2'（1）/ n'的不可区分的铁磁模型。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号