Data for: Pressure-induced amorphization in ultrahard ceramics: A thermodynamics-based theory for boron carbide

Here, two sets of data have been included to demonstrate computational prediction of Raman spectrum for amorphized boron carbide. The first set pertains to DFT simulations using the ABINIT software, while the second is for MD simulations using LAMMPS. According to the new theory presented in this paper, pressure-induced amorphization is concomitant with high temperatures and results in local melting of the material. Such molten regions lose their original crystalline structure, and that loss in structural integrity sustains even on cooling. MD studies were utilized to present this phenomenon and the relevant data is included. The theory also provides a new rationale for Raman spectra of amorphized boron carbide, wherein, amorphization causes local volume increase and causes compression in the surrounding crystalline matrix. The new amorphization peaks arise from compressed crystalline material; crystalline peaks migrate (shift) and give rise to the new spectrum. DFT simulations were conducted to estimate such migrations on application of different levels of pressure. The included DFT data can be used to visualize predictions of DFT-evaluated Raman peaks at different compressive pressures along with included experimental data of pristine and amorphous Raman spectra for boron carbide.本数据集包含两组数据，用于展示非晶化碳化硼的拉曼光谱计算预测结果。第一组数据基于使用ABINIT软件开展的密度泛函理论（Density Functional Theory, DFT）模拟，第二组则为使用LAMMPS完成的分子动力学（Molecular Dynamics, MD）模拟。根据本文提出的新理论，压力诱导的非晶化过程与高温相伴而生，并会导致材料发生局部熔融。此类熔融区域会丧失原有的晶体结构，且这种结构完整性的丧失在冷却后仍会持续存在。本研究借助分子动力学模拟阐释了该现象，相关数据已收录于本数据集。该理论还为非晶化碳化硼的拉曼光谱提供了全新的解释逻辑：非晶化过程会引发局部体积膨胀，并对周围的晶体基质产生挤压作用。新出现的非晶化特征峰源自受挤压的晶体材料；晶体特征峰发生偏移，进而形成新的拉曼光谱。本研究开展了密度泛函理论模拟，以估算不同施压条件下晶体特征峰的偏移情况。本次收录的密度泛函理论数据，可用于可视化不同施压条件下经密度泛函理论评估得到的拉曼峰预测结果，同时配套收录了原始态与非晶态碳化硼的拉曼光谱实验数据。