论文标题
BACU2AS2的新型多态性相：通量对新相生长中新相形成的影响
Novel polymorphic phase of BaCu2As2: impact of flux for new phase formation in crystal growth
论文作者
论文摘要
在这项工作中，我们彻底研究了通量组成和温度对BACU2AS2化合物晶体生长的影响。 PB和CUAS自通料产生众所周知的α相THCR2SI2型结构（Z = 2），这是BacU2AS2（\ B {eta}相）的新的多态相（\ b {eta}相），具有更大的C层次参数（z = 10），可以通过THCR2SI2SI2SI2SI2SI2SI2SI2SI2-exe2-eNTEPTER（z = 10）进行。 生长。我们通过单晶X射线衍射，透射电子显微镜（TEM）和扫描透射电子显微镜（STEM）研究来表征这种结构。此外，我们将这种新的多态性间生间结构与α相BACU2AS2（THCR2SI2类型为z = 2）和\ b {eta} -phase bacu2sb2（thcr2si2和cabe2ge2类型具有z = 6）的生长，均与同一空间I4/mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm。电运输研究显示，在5 K时，在5 K和7 T的磁场下，P型载体和磁倍率高达22％。我们的工作提出了一种新的途径，可以通过材料合成期间通过通量和温度控制发现新的多态性结构。
In this work, we have thoroughly studied the effects of flux composition and temperature on the crystal growth of the BaCu2As2 compound. While Pb and CuAs self-flux produce the well-known α-phase ThCr2Si2-type structure (Z=2), a new polymorphic phase of BaCu2As2 (\b{eta} phase) with a much larger c lattice parameter (Z=10), which could be considered an intergrowth of the ThCr2Si2- and CaBe2Ge2-type structures, has been discovered via Sn flux growth. We have characterized this structure through single-crystal X-ray diffraction, transmission electron microscopy (TEM), and scanning transmission electron microscopy (STEM) studies. Furthermore, we compare this new polymorphic intergrowth structure with the α-phase BaCu2As2 (ThCr2Si2 type with Z=2) and the \b{eta}-phase BaCu2Sb2 (intergrowth of ThCr2Si2 and CaBe2Ge2 types with Z=6), both with the same space group I4/mmm. Electrical transport studies reveal p-type carriers and magnetoresistivity up to 22% at 5 K and under a magnetic field of 7 T. Our work suggests a new route for the discovery of new polymorphic structures through flux and temperature control during material synthesis.
