摘要
本文采用恒温加热超声与低温高真空退火的两步制备工艺法成功合成了钾掺杂2-苯基喹啉分子晶体。直流和交流的磁性测量结果表明,掺杂晶体具有居里温度约为50.0 K的弱铁磁性。结合XRD测试和第一性原理计算结果发现,掺杂晶体属于P1空间对称群,且钾原子和2-苯基喹啉分子的摩尔比为1:1。电子结构的计算和拉曼光谱的研究表明,K-4s电子转移到了C-2p轨道上并形成了局域磁矩,晶胞中ab平面内相邻分子磁矩之间具有非共线的反铁磁排列,沿着c轴方向上层间相邻分子磁矩之间为铁磁排列,每个晶胞具有0.004 μB的净磁矩,由此导致了弱铁磁性的形成。本文的研究结果为开发和设计基于芳香烃的高温有机分子磁体提供了一条重要的线索和思路。
In this paper, potassium-doped 2-phenylquinoline molecular crystals were successfully synthesized by a two-step synthesis method involving constant temperature heating with ultrasound and low-temperature high vacuum annealing. The DC and AC magnetic measurements showed that the doped crystals have weak ferromagnetic properties with a Curie temperature of about 50.0 K. Combined with XRD testing and first-principles calculations, it was discovered that the doped crystals belong to the P1 spatial symmetry group, with a molar ratio of potassium atoms to 2-phenylquinoline molecules being 1:1. Electronic structure calculations and Raman spectros-copy showed that K-4s electrons were transferred to the C-2p orbitals and formed local magnetic moments. There exists a noncollinear antiferromagnetic arrangement between adjacent molecular magnetic moments in the ab plane of the crystal cell, the c-axis direction prefers a ferromagnetic arrangement, and each cell has a net magnetic moment of 0.004 μB, leading to the formation of weak ferromagnetism. Our finding provides an important clue for the development and design of high-temperature organic molecular magnets based on aromatic hydrocarbons.
出处
《凝聚态物理学进展》
2023年第3期54-64,共11页
Advances in Condensed Matter Physics
