Huang Shengxuan, Wu Xiang, Niu Jingjing, Qin Shan
Key Laboratory of Orogenic Belts and Crustal Evolution, MOE, School of Earth and Space Sciences, Peking University Beijing 100871 P. R. China.
State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences Wuhan 430074 P. R. China
RSC Adv. 2018 Jul 9;8(43):24561-24570. doi: 10.1039/c8ra04537b. eCollection 2018 Jul 2.
As the only half-metallic ferromagnetic material in 3d transition metal dioxides, CrO has attracted great scientific interest from materials science to physical chemistry. Here, an investigation into the structural, magnetic and electronic properties of CrO under high pressure has been conducted by first-principles calculations based on density functional theory. Static calculations have predicted that CrO undergoes structural transitions with the sequence of rutile-type → CaCl-type → pyrite-type → → (FeP-type→) 4/ at high pressures. In addition, a transition from the ferromagnetic state to the non-magnetic state with the magnetic collapse of Cr is observed in CrO at the pyrite- transition. This transition also delocalizes the 3d electrons of Cr and leads to a metallic character of CrO. The equation of state, elasticity and band gap for each energetically favorable phase of CrO are determined. Our results not only bridge the gap about the high-pressure behavior of CrO in previous studies but also extend our understanding of its properties up to multimegabar conditions. According to previous data and present results, we further discuss and summarize the high-pressure behavior of various AO compounds. This can contribute to investigating properties of other AO compounds or exploring novel materials at high pressures.
作为3d过渡金属二氧化物中唯一的半金属铁磁材料，CrO已引起从材料科学到物理化学等领域极大的科学兴趣。在此，基于密度泛函理论的第一性原理计算对高压下CrO的结构、磁性和电子性质进行了研究。静态计算预测，CrO在高压下会经历金红石型→CaCl型→黄铁矿型→→（FeP型→）4/的结构转变。此外，在黄铁矿型转变时，在CrO中观察到随着Cr的磁性崩溃，从铁磁态到非磁态的转变。这种转变还使Cr的3d电子离域，并导致CrO具有金属特性。确定了CrO每个能量有利相的状态方程、弹性和带隙。我们的结果不仅弥合了先前研究中关于CrO高压行为的差距，还将我们对其性质的理解扩展到了多兆巴条件。根据先前的数据和目前的结果，我们进一步讨论并总结了各种AO化合物的高压行为。这有助于研究其他AO化合物的性质或在高压下探索新型材料。
