
Citation: | KANG Xu, LIU Jin. Phase Retrieval and Reconstruction of Coherent Diffraction Imaging[J]. Chinese Journal of High Pressure Physics, 2019, 33(3): 030105. doi: 10.11858/gywlxb.20190761 |
Mn+1AXn相材料是三元层状化合物(简称MAX相材料),其中:M代表Ti、V、Zr等过渡金属元素;A代表A组元素;X代表C或者N;n=1, 2, 3, ···[1]。MAX相这一概念最早由Barsoum[2]提出,这类材料普遍具有陶瓷材料和金属材料的双重特性,可在高压、高温、强腐蚀等极端条件下稳定存在[3-4],并表现出较好的稳定性和抗氧化性,具有极其重要的研究价值和广阔的发展前景[5],因此探究高压等极端状态下的晶体性质变化具有重要意义。
近年来,有关三元层状Mn+1AXn相材料的研究很多,主要集中在211相、312相和413相[6]。随着研究的深入,Mn+1A2Xn双“A”层221相、322相等结构被陆续得到,第一种双“A”层MAX相化合物Mo2Ga2C由Hu等[7]于2015年成功制备,2016年Thore等[8]通过第一性原理计算预测出V2Ga2C的存在,V2Ga2C、Ti3Au2C2等双“A”型MAX相的理论预测和实验制备极大地丰富了MAX族化合物[9]。V2Ga2C 是典型的由理论预测得到的新型双“A”层MAX相材料, Thore等[10]根据声子谱没有虚频判定V2Ga2C具有稳定结构,研究发现这类双“A”层的MAX相材料普遍具有较强的金属性,如更好的机械延展性、易于加工等[11]。目前,常压下V2Ga2C的研究日趋丰富,受限于实验条件的复杂性,高压下V2Ga2C的结构、电子、弹性等性能研究较为困难,为此基于密度泛函理论的第一性原理计算能够很好地解决这一问题。
本研究通过第一性原理对V2Ga2C六方结构的能带结构、态密度等电子结构和弹性性能等力学性质进行计算,根据玻恩稳定准则等相关理论,预测高压状态下V2Ga2C结构的力学稳定性,并对高压下V2Ga2C的晶体结构、电子结构和弹性性质等进行分析,为新型双“A”型Mn+1A2Xn相的相关研究提供理论参考。
采用第一性原理计算方法,运用基于密度泛函理论的Materials Studio软件中的CASTEP量子力学程序[12-13],选用倒易点阵空间表征的Cepeley-Alder超软赝势[14]。利用总能量的平面波赝势替代离子势,并通过广义梯度近似(Generalized gradient approximation, GGA)中的PBE(Perdew, Burke and Ernzerhof)[15-16]方法对电子间的相互作用和相关势进行校正。为确保总能量和原子间的作用力最小化,采用Broyden-Fletcher-Goldfarb-Shanno(BFGS)算法,布里渊区K点网格数为17 × 17 × 3,平面波截断能选取550 eV。进行原胞的几何优化(Geometry)时,能量收敛标准为5×10−6 eV/atom,最大作用力为0.01 eV/Å,应力偏差小于0.02 GPa,自洽场收敛精度为5×10−7 eV/atom。
V2Ga2C为六方晶系,空间群是P63/mmc,每个晶胞有10个原子,晶体结构见图1。V2Ga2C晶体与常见的V2GaC的结构和性质类似,晶胞键角
为了研究高压对V2Ga2C晶胞结构的影响,在0~70 GPa压强范围内以10 GPa为间隔进行结构优化,得到V2Ga2C晶胞的相对晶格参数变化情况,见图2。从图2可以看出,随着压强增大,晶格常数a、c和体积V均有不同程度的减小,同时在压强范围内V2Ga2C晶胞表现出较好的可压缩性,其中相对键长比a/a0和c/c0从1逐渐减小到0.9019和0.9331,相对晶格参数c/a从0 GPa的6.0362上升到70 GPa的6.2455,c轴较a轴随压强增大收缩得较慢,且键长的减小导致了晶胞体积V的缩小,上述晶胞参数的变化均体现了V2Ga2C的各向异性。此外,根据计算得到的V2Ga2C晶胞在不同压力下的晶格参数及相对晶格常数a/a0、c/c0、c/a和相对晶胞体积V/V0的变化趋势平缓,可判定在0~70 GPa压力范围内V2Ga2C很难发生相变,即本研究利用图1的V2Ga2C结构探究压力对其电子性质、弹性性质的影响是合理准确的。
力学稳定性是晶体材料稳定存在的重要因素。为研究压强对V2Ga2C晶胞力学稳定性的影响,从0 GPa开始,以每10 GPa为一个间隔进行结构优化,通过不同压强下的弹性常数预测V2Ga2C晶胞的力学稳定性。通过各个压强状态下V2Ga2C晶胞的结构优化,得到0~80 GPa不同压强状态下的晶体结构,各压强状态下的弹性常数见表1。
Pressure/GPa | C11/GPa | C33/GPa | C44/GPa | C12/GPa | C13/GPa |
0 | 275.07 | 309.04 | 88.92 | 65.69 | 48.31 |
10 | 325.89 | 437.85 | 103.70 | 79.38 | 101.23 |
20 | 392.18 | 492.57 | 112.70 | 113.70 | 122.66 |
30 | 475.27 | 582.90 | 99.80 | 176.94 | 174.81 |
40 | 462.17 | 636.80 | 103.00 | 156.69 | 180.10 |
50 | 524.87 | 696.25 | 51.41 | 228.45 | 221.66 |
60 | 558.67 | 743.34 | 29.53 | 220.05 | 219.34 |
70 | 640.36 | 854.90 | 4.53 | 280.99 | 275.36 |
80 | 618.66 | 892.67 | −84.84 | 305.13 | 305.24 |
弹性常数是晶体对作用力反应最直观的数据体现。根据V2Ga2C的晶胞结构,V2Ga2C晶体的弹性常数具有对称性,即C11= C22,C13=C31=C32=C23,C12=C21,C44=C55。由表1数据可知,弹性常数C11、C33随压强的增大逐渐增大,C44先增大后逐渐变小直至减小到负数,C12、C13和C66也有不同程度的增大。V2Ga2C晶胞为六方晶系,因此可以通过玻恩稳定准则[17]、正交系统的力学稳定性公式[18]以及弹性常数的变化规律,预测V2Ga2C六方三元层状化合物的力学稳定性。
玻恩稳定准则可写为
C12>0,C33>0,C44>0,C11−C12>0,(C11+C12)C33−2C213>0 |
(1) |
验证V2Ga2C晶胞正交系统力学稳定性的公式为
Cij>0(i=j,0⩽i⩽6),C11+C22−2C12>0,C11+C33−2C13>0,C22+C33−2C23>0,C11+C22+C33+2C12+2C13+2C23>0 |
(2) |
将表1的弹性常数代入式(1)、式(2),可知V2Ga2C晶胞在0~70 GPa符合式(1),在80 GPa时不符合式(1)。因此六方V2Ga2C晶胞的的弹性常数在0~70 GPa压强范围内处于力学稳定状态,80 GPa下V2Ga2C晶胞结构不稳定。
为了研究压强对V2Ga2C晶体弹性性质的影响,在不同的压强下对晶胞结构进行优化,在此基础上计算不同压强状态下的弹性常数(见表1)。弹性常数C11、C22和C33分别表示晶胞受压沿a、b和c轴的线性压缩阻力,C11、C22较小而C33最大,说明V2Ga2C在a、b轴上容易压缩,在c轴上难压缩;弹性常数C44、C55和C66与材料抗剪切变形能力有关,C44还与硬度有关,随压强增大而减小的C44表明V2Ga2C材料抵抗形变的能力一般。
根据Voigt-Reuss-Hill近似理论[19],V2Ga2C的体积弹性模量B的最大值BV、最小值BR和平均值BH,以及剪切弹性模量G的最大值GV、最小值GR和平均值GH可以通过式(3)~式(8)得到
BV=2(C11+C12)+C33+4C139 |
(3) |
BR=(C11+C12)C33−2C213C11+C12+2C33−4C13 |
(4) |
BH=BV+BR2 |
(5) |
GV=C11+C12+2C33−4C13+12C55+12C663 |
(6) |
GR=52[(C11+C12)C33−2C213]C55C663BVC55C66+[(C11+C12)C33−2C213](C55+C66) |
(7) |
GH=GV+GR2 |
(8) |
根据Pugh准则[17]可以鉴别晶体的韧脆性,BH/GH < 1.74为脆性材料,相反为韧性材料。根据表1弹性常数和式(3)~式(8),可以计算体积模量BH和剪切模量GH,得到压强与BH/GH的关系曲线,见图3。从图3可以明显看出,压强小于20.15 GPa时,V2Ga2C表现为脆性材料,压强为20.15~70.00 GPa时表现为韧性材料。此外,通过式(9)可以预测维氏硬度(HV)的变化(其中K = GH/BH,HV的单位为GPa),维氏硬度随压强的变化见图4。从图4中曲线的变化趋势可以看出,维氏硬度随着压强的增大逐渐变小,原因是V2Ga2C晶胞的键长和a、b轴随压强的增大急剧压缩,故维氏硬度随之减小。
HV=0.92K1.137G0.708H |
(9) |
然而遗憾的是,目前公开发表的有关V2Ga2C在高压状态下的力学性能研究报道较少,难以与本计算得到的理论预测进行对比分析。
为探究压强与V2Ga2C电子性质的关系,在0~70 GPa的压强范围内通过GGA-PBE密度泛函理论计算,得到V2Ga2C的能带结构图、电子总态密度图,其中0 eV处的虚线表示费米能。
下面以0、35和70 GPa的能带结构为例进行分析,如图5所示。从图5可以明显看出,0 GPa下V2Ga2C无带隙,35 GPa下仍无带隙,直到接近力学稳定临界状态的70 GPa下仍未产生带隙,总体上能带曲线仅有很小幅度的变化。由此可知,在力学稳定范围内,V2Ga2C均无带隙,且压强的增加对能带结构的影响很小,即V2Ga2C材料为导体材料且压强对其影响较小或几乎没有影响。
电子态密度也是V2Ga2C电子性质的重要组成部分,选取0、35和70 GPa状态下的电子态密度分析压强与电子态密度的关系,见图6。由图6可知,随着压强增大,V2Ga2C的总态密度在费米能级附近变动较小,对电子性质影响较小。
基于密度泛函理论的第一性原理,研究了压强对V2Ga2C晶体的力学稳定性及压强对V2Ga2C结构、弹性和电子性质的影响。根据玻恩稳定准则预测了V2Ga2C结构稳定存在的压强区间为0~70 GPa,并通过正交系统的力学稳定公式验证结果可靠。同时,研究了0~70 GPa压强下V2Ga2C的晶体结构、弹性性质与电子结构,压强使V2Ga2C压缩,体积、相对晶胞参数a/a0、c/c0等均有不同程度的减小,都体现了V2Ga2C具有各向异性;随着压强增大,通过弹性常数可知V2Ga2C在a、b轴上较c轴易压缩,且在20.15 GPa时从韧性转变为脆性,其硬度也随之变小;从V2Ga2C在各个压强状态下的态密度和能带结构可知,在力学稳定的条件下压强对V2Ga2C材料的电子性质影响不大。然而目前有关V2Ga2C材料的研究较少,希望本研究结果可以为双“A”型MAX相材料的实验制备和理论研究提供参考。
[1] |
CHAO W, HARTENECK B D, LIDDLE J A, et al. Soft X-ray microscopy at a spatial resolution better than 15 nm [J]. Nature, 2005, 435(7046): 1210. doi: 10.1038/nature03719
|
[2] |
BARBER J L, BARNES C W, SANDBERG R L, et al. Diffractive imaging at large fresnel number: challenge of dynamic mesoscale imaging with hard X-rays [J]. Physical Review B, 2014, 89(18): 184105. doi: 10.1103/PhysRevB.89.184105
|
[3] |
XIAO X H, SHEN Q. Wave propagation and phase retrieval in fresnel diffraction by a distorted-object approach [J]. Physical Review B, 2005, 72(3): 033103. doi: 10.1103/PhysRevB.72.033103
|
[4] |
MIAO J W, AMONETTE J E, NISHINO Y, et al. Direct determination of the absolute electron density of nanostructured and disordered materials at sub-10-nm resolution [J]. Physical Review B, 200, 68(1): 012201.
|
[5] |
SAYER D. Some implications of a theorem due to shannon [J]. Acta Crystallographica, 1952, 5: 843.
|
[6] |
GERCHBERG R W, SAXTON W O. A practical algorithm for the determination of phase from image and diffraction plane pictures [J]. Optik, 1972, 35: 237.
|
[7] |
FIENUP J R. Phase retrieval algorithm: a comparison [J]. Applied Optics, 1982, 21: 2758. doi: 10.1364/AO.21.002758
|
[8] |
ELSER V. Phase retrieval by iterated projections [J]. Journal of the Optical Society of America, 2003, 20(1): 40. doi: 10.1364/JOSAA.20.000040
|
[9] |
CHEN C C, MIAO J, WANG C W, et al. Application of optimization technique to noncrystalline X-ray diffraction microscopy: guided hybrid input-output method [J]. Physical Review B, 2007, 76(6): 064113. doi: 10.1103/PhysRevB.76.064113
|
[10] |
LUKE D R. Relaxed averaged alternating reflections for diffraction imaging [J]. Inverse Problems, 2005, 21: 37. doi: 10.1088/0266-5611/21/1/004
|
[11] |
MARCHESINI S, HE H, CHAPMAN H N, et al. X-ray image reconstruction from a diffraction pattern alone [J]. Physical Review B, 2003, 68: 140101. doi: 10.1103/PhysRevB.68.140101
|
[12] |
MIAO J, SYAER D, CHAPMAN H N. Phase retrieval from the magnitude of the fourier transforms of nonperiodic objects [J]. Josa A, 1998, 15: 1662. doi: 10.1364/JOSAA.15.001662
|
[13] |
周光照, 佟亚军, 陈灿, 等. 相干X射线衍射成像的数字模拟研究 [J]. 物理学报, 2011, 60(2): 028701.
ZHOU G Z, TONG Y J, CHEN C, et al. Digital simulation for coherent X-ray diffractive imaging [J]. Acta Physica Sinica, 2011, 60(2): 028701.
|
[14] |
VARTANYANTS I A, ROBINSON I K. Partial coherence effects on the imaging of small crystals using coherent X-ray diffraction [J]. Journal of Physics: Condensed Matter, 2001, 13(47): 10593. doi: 10.1088/0953-8984/13/47/305
|
[15] |
MIAO J W, CHARALAMBOUS P, KIRZ J, et al. Extending the methodology of X-ray crystallography to allow imaging of micrometer-sized non-crystalline specimens [J]. Nature, 1999, 400: 342. doi: 10.1038/22498
|
[16] |
MIAO J W, NISHINO Y, KOHNURA Y, et al. Quantitative image reconstruction of GaN quantum dots from oversampled diffraction intensities alone [J]. Physical Review Letters, 2005, 95(8): 085503. doi: 10.1103/PhysRevLett.95.085503
|
[17] |
NISHINO Y, TAKAHASHI Y, IMAMOTO N, et al. Three-dimensional visualization of a human chromosome using coherent X-ray diffraction [J]. Physical Review Letters, 2009, 102(1): 018101. doi: 10.1103/PhysRevLett.102.018101
|
[18] |
EKEBERG T, SVENDA M, ABERGEL C, et al. Three-dimensional reconstruction of the giant mimivirus particle with an X-ray free-electron laser [J]. Physical Review Letters, 2015, 114(9): 098102. doi: 10.1103/PhysRevLett.114.098102
|
[19] |
DUANE N T, ELSER V. Reconstruction algorithm for single-particle diffraction imaging experiments [J]. Physical Review E, 2009, 80(2): 026705. doi: 10.1103/PhysRevE.80.026705
|
[20] |
MIAO J W, CHEN C C, SONG C, et al. Three-dimensional GaN-Ga2O3 core shell structure revealed by X-ray diffraction microscopy [J]. Physical Review Letters, 2006, 97(21): 215503. doi: 10.1103/PhysRevLett.97.215503
|
[21] |
TAKAHASHI Y, NISHINO Y, TSUTSUMI R, et al. High-resolution projection image reconstruction of thick objects by hard X-ray diffraction microscopy [J]. Physical Review B, 2010, 82(21): 214102. doi: 10.1103/PhysRevB.82.214102
|
[22] |
THIBAULT P, DIEROLF M, MENZEL A, et al. High-resolution scanning X-ray diffraction microscopy [J]. Science, 2008, 321(5887): 379. doi: 10.1126/science.1158573
|
[23] |
RODENBURG J M, HURST A C, CULLIS A G, et al. Hard-X-ray lensless imaging of extended objects [J]. Physical Review Letters, 2007, 98(3): 034801. doi: 10.1103/PhysRevLett.98.034801
|
[24] |
KLAUS G, PIERRE T, SEBASTIAN K, et al. Quantitative biological imaging by ptychographic X-ray diffraction microscopy [J]. Proceedings of the National Academy of Sciences of the United States of America, 2010, 107(2): 529. doi: 10.1073/pnas.0905846107
|
[25] |
DIEROLF M, MENZEL A, THIBAULT P, et al. Ptychographic X-ray computed tomography at the nanoscale [J]. Nature, 2010, 467(7314): 436. doi: 10.1038/nature09419
|
[26] |
ROBINSON I K, VARTANYANTS I A, WILLIAMS G J, et al. Reconstruction of the shapes of gold nanocrystals using coherent X-ray diffraction [J]. Physical Review Letters, 2001, 87(19): 195505. doi: 10.1103/PhysRevLett.87.195505
|
[27] |
WILLIAMS G J, PFEIFER M A, VARTANYANTS I A, et al. Three-dimensional imaging of microstructure in Au nanocrystals [J]. Physical Review Letters, 2003, 90(17): 175501. doi: 10.1103/PhysRevLett.90.175501
|
[28] |
PFEIFER M A, WILLIAMS G J, VARTANYANTS I A, et al. Three-dimensional mapping of a deformation field inside a nanocrystal [J]. Nature, 2006, 442(7098): 63. doi: 10.1038/nature04867
|
[29] |
NEWTON M C, LEAKE S J, HARDER R, et al. Three-dimensional imaging of strain in a single ZnO nanorod [J]. Nature Materials, 2010, 9(2): 279.
|
[30] |
HARDER R, ROBINSON I. Coherent X-ray diffraction imaging of strain at the nanoscale [J]. Nature Materials, 2009, 8(4): 291. doi: 10.1038/nmat2400
|
[31] |
GANG X, OUSSAMA M, MANFRED R, et al. Coherent X-ray diffraction imaging and characterization of strain in silicon-on-insulator nanostructures [J]. Advanced Materials, 2014, 26(46): 7747. doi: 10.1002/adma.v26.46
|
[1] | ZHENG Feili, YAN Jian, HUANG Yanping, LUO Xuan, CHI Zhenhua, LYU Xindeng, CUI Tian. Physical Properties of Two-Dimensional Layered FePSe3 under High Pressure[J]. Chinese Journal of High Pressure Physics, 2023, 37(2): 021101. doi: 10.11858/gywlxb.20230617 |
[2] | LIU Haowei, SU Buyun, QIU Ji, LI Zhiqiang. Numerical Simulation of Multiaxial Creep Behavior of 2D Anisotropic Cellular Materials[J]. Chinese Journal of High Pressure Physics, 2020, 34(6): 064202. doi: 10.11858/gywlxb.20200561 |
[3] | ZHAO Haibo, XIAO Bo, BAI Jinsong, DUAN Shuchao, WANG Ganghua, KAN Mingxian, CHEN Fang. Simulation of Two-Dimensional Multi-Material Compressible Flows Using Lagrangian Methods[J]. Chinese Journal of High Pressure Physics, 2018, 32(4): 042303. doi: 10.11858/gywlxb.20170694 |
[4] | LIU Hai-Feng, HAN Li. Numerical Simulation of Dynamic Mechanical Behavior of Concrete with Two-dimensional Random Distribution of Coarse Aggregate[J]. Chinese Journal of High Pressure Physics, 2016, 30(3): 191-199. doi: 10.11858/gywlxb.2016.03.003 |
[5] | QI Mei-Lan, RAN Xiao-Xia, BIE Bi-Xiong, FAN Duan, LI Ping. Quantify the Errors of Two-Dimensional Technique by Comparing to Three-Dimensional Measurement Method on Evaluating Damage in Shocked Ultrapure Aluminum[J]. Chinese Journal of High Pressure Physics, 2015, 29(4): 273-278. doi: 10.11858/gywlxb.2015.04.006 |
[6] | WANG Tao, BAI Jin-Song, LI Ping, TAO Gang, JIANG Yang, ZHONG Min. Two and Three Dimensional Numerical Investigations of the Single-Mode Richtmyer-Meshkov Instability[J]. Chinese Journal of High Pressure Physics, 2013, 27(2): 277-286. doi: 10.11858/gywlxb.2013.02.016 |
[7] | LI Lei, BAI Jin-Song, LIU Kun, LI Ping. 2-D GEL Coupling Method and Its Numerical Simulation on Vessel to Explosion Impact Load[J]. Chinese Journal of High Pressure Physics, 2011, 25(6): 549-556. doi: 10.11858/gywlxb.2011.06.011 |
[8] | LI Cheng-Bing, WU Guo-Dong, JING Fu-Qian. Two-Dimensional Numerical Simulation of Explosion for Premixed CH4-O2-N2 Mixture[J]. Chinese Journal of High Pressure Physics, 2009, 23(5): 367-376 . doi: 10.11858/gywlxb.2009.05.008 |
[9] | WANG Tao, BAI Jing-Song, LI Ping. Two-Dimensional Numerical Simulation of Gas/Liquid Interface Instability[J]. Chinese Journal of High Pressure Physics, 2008, 22(3): 298-304 . doi: 10.11858/gywlxb.2008.03.013 |
[10] | WANG Su-Qin, GU Min. Synthesis and Characterization of Two-Dimensional Rh-C60 Polymer[J]. Chinese Journal of High Pressure Physics, 2008, 22(1): 35-38 . doi: 10.11858/gywlxb.2008.01.008 |
[11] | LI Cheng-Bing, PEI Ming-Jing, SHEN Zhao-Wu. Three-Dimensional Numerical Simulation of the High Velocity Rod-Shaped Projectile[J]. Chinese Journal of High Pressure Physics, 2007, 21(2): 165-172 . doi: 10.11858/gywlxb.2007.02.008 |
[12] | HAO Li, NING Jian-Guo, WANG Cheng. 2D Numerical Simulation of Explosive Damage Effect on Obstacles in Water[J]. Chinese Journal of High Pressure Physics, 2006, 20(1): 39-44 . doi: 10.11858/gywlxb.2006.01.009 |
[13] | LI Zi-Jun, LI Gang. Magnetic Field and Temperature Effects on the Self-Trapping Energy of the 2-D Spin Magnetopolaron in an InAs Crystal[J]. Chinese Journal of High Pressure Physics, 2005, 19(1): 45-50 . doi: 10.11858/gywlxb.2005.01.009 |
[14] | BAI Jing-Song, LI Ping, ZHONG Min, JIANG Yang, ZHANG Zhan-Ji, YU Ji-Dong. Numerical Simulation of Different Cavities Compression by the High Pressure[J]. Chinese Journal of High Pressure Physics, 2005, 19(1): 17-23 . doi: 10.11858/gywlxb.2005.01.004 |
[15] | TAN Fu-Li, LI Yong-Chi, GUO Yang, CAO Jie-Dong. One-Dimensional and Two-Dimensional Computation of Metal Spallation Induced by Laser[J]. Chinese Journal of High Pressure Physics, 2005, 19(1): 24-28 . doi: 10.11858/gywlxb.2005.01.005 |
[16] | DONG Gang, FAN Bao-Chun, XIE Bo. Two-Dimensional Simulation of Transient Detonation Process for H2-O2-N2 Mixture[J]. Chinese Journal of High Pressure Physics, 2004, 18(1): 40-46 . doi: 10.11858/gywlxb.2004.01.008 |
[17] | LIANG Long-He, CAO Ju-Zhen, YUAN Xian-Chun. 2-D Nummerical Simulation of Characteristics of Underwater Explosions[J]. Chinese Journal of High Pressure Physics, 2004, 18(3): 203-208 . doi: 10.11858/gywlxb.2004.03.003 |
[18] | XU Li, SUN Jin-Shan. A Comparative Study of the Evolution of R-T Instability in Two and Three Dimensions[J]. Chinese Journal of High Pressure Physics, 2003, 17(3): 180-186 . doi: 10.11858/gywlxb.2003.03.004 |
[19] | ZHANG Zhen-Yu, WANG Zhi-Bing, HUANG Tie-Jun, LU Fang-Yun, HUAN Shi. Two-Dimensional Numerical Simulation for the Inertial Effect of EMV Gauge Moving with Detonation Wave[J]. Chinese Journal of High Pressure Physics, 1999, 13(3): 187-191 . doi: 10.11858/gywlxb.1999.03.006 |
[20] | ZHAO Min, SUN Feng-Guo, TANG Rong-Qi. Numerical Calculation for Latent Heat and Thermal Expansion Coefficient of a Two Dimensional Hard Disk System[J]. Chinese Journal of High Pressure Physics, 1993, 7(2): 152-155 . doi: 10.11858/gywlxb.1993.02.013 |
Pressure/GPa | C11/GPa | C33/GPa | C44/GPa | C12/GPa | C13/GPa |
0 | 275.07 | 309.04 | 88.92 | 65.69 | 48.31 |
10 | 325.89 | 437.85 | 103.70 | 79.38 | 101.23 |
20 | 392.18 | 492.57 | 112.70 | 113.70 | 122.66 |
30 | 475.27 | 582.90 | 99.80 | 176.94 | 174.81 |
40 | 462.17 | 636.80 | 103.00 | 156.69 | 180.10 |
50 | 524.87 | 696.25 | 51.41 | 228.45 | 221.66 |
60 | 558.67 | 743.34 | 29.53 | 220.05 | 219.34 |
70 | 640.36 | 854.90 | 4.53 | 280.99 | 275.36 |
80 | 618.66 | 892.67 | −84.84 | 305.13 | 305.24 |