Effect of Si on acoustic velocities of bcc-Fe and fcc-Feshear softening of Fe-Si alloys and its impl

• 作 者: Mingqiang Hou Hong Liu Yingwei Fei Zhisheng Zhao Li Zhang Yoshio Kono Daijo Ikuta
• 机 构: CenterforHighPressureScienceandTechnologyAdvancedResearch,Shanghai201203,China;GeophysicalLaboratory
• 出 处: 第十八届中国高压科学学术会议
• 发表日期: 2016年7期
• 关键词: Earth's inner core acoustic velocity shear softening high pressure

　　The ultra-low shear wave velocities(VS)of the Earths inner core are still mysterious.Mechanisms of defects,partial melting,temperature effect,and spin-pairing transition are employed to explain this phenomenon.Here we proposed a new mechanism.Acoustic velocities of Fe,Fe97Si3,and Fe94Si6 in bcc and fcc phases are studied up to 7.1 GPa and 1200 K.Experimental results illustrated that the incorporation of Si could significantly increase compressional wave velocity(VP)and decrease shear wave velocity of bcc-Fe.For fcc-Fe,Si could slightly increase its VP and significantly reduce its VS.