Acoustic velocities, elasticity, and pressure-induced elastic softening in compressed neodymium. (April 2021)

• Record Type: Journal Article
• Authors: Zou, Yongtao; Li, Mu; Deng, Liwei; Zhang, Hua; Guo, Xiaoyang; Li, Lu; Wu, Sizhong; Huang, Taiwu; Li, Hui; Cai, Xun; Zhuo, Hongbin; Ruan, Shuangchen; Zhou, Cangtao; Li, Baosheng
• Is Part Of: Mechanics of materials. Volume 155(2021)
• Publication Date: 2021-04
• Subjects: Neodymium -- Structural instability -- Elastic/mechanical properties -- Ultrasonic measurements -- Synchrotron X-ray diffraction -- High pressure; Strength of materials -- Periodicals; Mechanics, Applied -- Periodicals; Résistance des matériaux -- Périodiques; Mécanique appliquée -- Périodiques; Mechanics, Applied; Strength of materials; Periodicals; Electronic journals; 620.11
• DOI: 10.1016/j.mechmat.2021.103776
• Languages: English
• ISSNs: 0167-6636

Abstract

Abstract: For the first time, the acoustic velocities and elasticity of double hexagonal close-packed neodymium (Nd) were measured at high pressure using ultrasonic interferometry in conjunction with synchrotron X-ray techniques. Both the compressional and shear wave velocities increased with an increase in pressure of up to ~5.4 GPa before they exhibited almost constant values upon further compression. This pressure-induced elastic wave velocity softening can be attributed to the structural instability in dhcp -Nd. From the current sound velocities and density data, we obtained new bulk and shear moduli as well as their pressure dependence for polycrystalline dhcp -Nd, yielding B 0 = 33.2(9) GPa, G 0 = 14.1(5) GPa, ∂ B / ∂ P = 3.6 ( 4 ), and ∂ G / ∂ P = 1.3 ( 2 ), while other elasticity-related/mechanical properties, including Young's modulus, Debye temperature, Poisson's ratio, and Grüneisen parameter, which are important parameters for the application of Nd in extreme environments, were also derived. Graphical abstract: Image 1 Highlights: Measuring sound velocities and elasticity of dhcp- Nd at high pressure by ultrasonic measurements and in situ x-ray techniques. Exploring pressure-induced elastic softening in compressed polycrystalline dhcp -Nd. Reporting new data on the acoustic velocities, elastic and mechanical properties of dhcp -Nd at high pressure.