标题： 声子异常、非谐性以及少层PtX2（X= S，Se）的热膨胀系数：温度依赖的拉曼研究 显示英文标题

标题： Phonon anomalies, Anharmonicity, and thermal expansion coefficient in few layered PtX2 (X= S, Se): A temperature dependent Raman study

摘要： 二维的第10族稀有过渡金属二硫属化物由于其丰富的物理性质和在纳米电子学、光电子学和自旋电子学中的潜在应用而引起了越来越多的关注。 其中，PtX2（X = S，Se）表现出由硫属原子的垂直方向Pz轨道杂化驱动的显著层间耦合。 在本工作中，我们对少层PtS2和PtSe2在约5至300 K的温度范围内进行了详细的温度和偏振分辨拉曼光谱研究。我们的研究涵盖了声子-声子相互作用、声子模的对称性分析、低频层间振动以及热膨胀系数的提取。 在约80 K和150 K时，PtS2出现明显的声子异常，包括峰位、线宽和强度的变化，而在约70 K和240 K时，PtSe2出现类似的异常，表明热动力学和振动动力学之间存在复杂的耦合。 这些结果为基于PtS2、PtSe2及相关二维材料的器件开发提供了有价值的见解，在这些材料中，层间相互作用、非谐效应和热膨胀行为起着关键作用。 显示英文摘要

摘要： Two-dimensional group-10 noble transition metal dichalcogenides have garnered growing attention due to their rich physical properties and promising applications across nanoelectronics, optoelectronics, and spintronics. Among them, PtX2 (X = S, Se) exhibits pronounced interlayer coupling driven by hybridization of the out-of-plane Pz orbitals of the chalcogen atoms. In this work, we present a detailed temperature and polarization-resolved Raman spectroscopic study of few-layer PtS2 and PtSe2 over the temperature range of ~ 5 to 300 K. Our study encompasses phonon-phonon interactions, symmetry analysis of phonon modes, low-frequency interlayer vibrations, and extraction of thermal expansion coefficients. Notable phonon anomalies in peak position, linewidth, and intensity emerge around ~ 80 K and 150 K for PtS2, and ~ 70 K and 240 K for PtSe2, indicating intricate coupling between thermal and vibrational dynamics. These results offer valuable insights for the development of devices based on PtS2, PtSe2, and related 2D materials, where interlayer interactions, anharmonic effects, and thermal expansion behaviour play crucial roles.