Structural, Elastic, and Electronic Properties of Antiperovskite Chromium-Based Carbides ACCr3 (A = Al and Ga)
Structural, Elastic, and Electronic Properties of Antiperovskite Chromium-Based Carbides ACCr3 (A = Al and Ga)
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DOI：
10.1155/2013/136274
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发表时间：
2013-01
影响因子：
1.5
通讯作者：
D. Shao;Wenjian Lu;Sheng-Ru Lin;P. Tong;Y. Sun
中科院分区：
文献类型：
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作者：
D. Shao;Wenjian Lu;Sheng-Ru Lin;P. Tong;Y. Sun
通过基于密度泛函理论(DFT)的第一性原理计算，对反钙钛矿铬基碳化物ACCr3进行了理论研究。结构优化表明，ACCr3的晶格参数与A位元素的半径基本成正比。计算的生成能表明AlCCr3和GaCCr3可以在常压下合成，并且在非磁性基态下是稳定的。在弹性常数计算的基础上，推导并讨论了一些弹性、力学和热学参数。AlCCr3和GaCCr3表现出韧性性质，并且可能具有相似的热性能。由电子结构分析发现，AlCCr3和GaCCr3存在跨费米能级的电子能带和空穴能带，表现出多能带性质。费米能级位于态密度(DOSS)峰附近，这导致了以Cr-3D电子为主的费米能级的大DOS。AlCCr3和GaCCr3的能带结构与超导反钙钛矿结构的MgCNi3非常相似。这种相似性可能使AlCCr3和GaCCr3表现出超导性，这需要在理论和实验上进行进一步的研究。
We theoretically investigated antiperovskite chromium-based carbides ACCr3 through the first-principles calculation based on density functional theory (DFT). The structure optimization shows that the lattice parameter of ACCr3 is basically proportional to the radius of A-site elements. The calculated formation energies show that AlCCr3 and GaCCr3 can be synthesized at ambient pressure and are stable with nonmagnetic ground states. Based on the calculation of elastic constants, some elastic, mechanical, and thermal parameters are derived and discussed. AlCCr3 and GaCCr3 show ductile natures and may have similar thermal properties. From the analysis of the electronic structures, it was found that there are electron and hole bands that cross the Fermi level for AlCCr3 and GaCCr3, indicating multiple-band natures. The Fermi level locates at the vicinity of the density of states (DOSs) peak, which leads to a large DOS at Fermi level dominated by Cr-3d electrons. The band structures of AlCCr3 and GaCCr3 are very similar to those of the superconducting antiperovskite MgCNi3. The similarity may make AlCCr3 and GaCCr3 behave superconductively, which needs to be further investigated in theoretical and experimental studies.