@article{5930c2a117b641d2ab1159922be65f45,
title = "X-ray diffraction study of aluminum carbide powder to 50 GPa",
abstract = "The crystal structure and equation of state (EOS) of aluminum carbide (Al4 C3) have been determined directly up to 50.1 GPa at room temperature by the synchrotron x-ray diffraction techniques. The results indicate that Al4 C3 remained in rhombohedral structure under all tested pressure-temperature conditions and exhibited anisotropic compressibility, with the c -axis more compressible than the a -axis. Fitting the experimental data to third order Birch-Murnaghan EOS yields a bulk modulus of KOT =233±6 GPa with its pressure derivative K OT′ =3.4±0.4, while the second-order EOS yields K OT =223±2 GPa.",
author = "Cheng Ji and Yanzhang Ma and Chyu, {Ming Chien} and Russell Knudson and Hongyang Zhu",
note = "Funding Information: We thank Jingzhu Hu and Quanzhong Guo for their technical support with the synchrotron x-ray diffraction measurements at Brookhaven National Laboratory, Dr. Chunxiao Gao and Dr. Emre Selvi for technical assistance and mentoring throughout the research, and Trevor Hannon for manuscript proofreading. This work is supported by the National Science Foundation (DMR-0619215), Defense Threat Reduction Agency (HDTRA1–09–0034), and Research Office (W911NF-09–1–0001). Table I. Unit cell parameters and volume of powdered Al 4 C 3 at pressures from refinement. P (GPa) A ({\AA}) C ({\AA}) V ( {\AA} 3 ) 1.6 3.3277(7) 24.890(7) 238.71(8) 3.6 3.317(1) 24.81(1) 236.5(1) 4.1 3.319(2) 24.81(2) 236.6(3) 4.8 3.316(2) 24.80(1) 236.2(2) 5.9 3.309(4) 24.78(2) 235.0(4) 6.6 3.306(2) 24.748(9) 234.3(2) 7.2 3.304(6) 24.72(3) 233.7(7) 7.9 3.303(3) 24.68(2) 233.1(4) 8.7 3.300(3) 24.65(2) 232.4(3) 9.9 3.294(3) 24.56(2) 230.8(4) 10.6 3.2922(7) 24.581(5) 230.73(9) 11.4 3.288(4) 24.52(8) 229.6(6) 13.6 3.287(3) 24.42(7) 228.5(5) 17.4 3.277(3) 24.17(6) 224.8(4) 21.5 3.263(2) 23.92(4) 220.6(3) 25.6 3.249(1) 23.81(5) 217.7(3) 28.2 3.245(4) 23.9(1) 218(1) 33.5 3.234(5) 23.7(2) 214(1) 45.2 3.193(4) 23.5(1) 207(1) 50.1 3.183(3) 23.2(1) 204.0(9) FIG. 1. Selected angle-dispersive diffraction patterns of powdered Al 4 C 3 . Numbers above diffraction patterns on the left are pressures in GPa. FIG. 2. Peak splitting at 17.4 GPa. FIG. 3. d -spacing vs pressure relations of powdered Al 4 C 3 . Solid lines are guides to the eyes. FIG. 4. Normalized lattice parameters of Al 4 C 3 as a function of pressure. Solid lines are guides to the eyes. These cell parameter error bars are from Rietveld analysis in software refinement. FIG. 5. The unit cell volumes of Al 4 C 3 at pressures and EOS. Solid line is the EOS plot from the third BM fitted data; dashed line is the EOS plot from the previous research (Ref. 12 ). Error bars show the error of volume obtained from volume refinement. ",
year = "2009",
doi = "10.1063/1.3246808",
language = "English",
volume = "106",
journal = "Journal of Applied Physics",
issn = "0021-8979",
publisher = "AIP Publishing",
number = "8",
}