A new Ca3MgSi2O8 compound and some of its thermodynamic properties

doi:10.1016/j.jssc.2017.08.005

CORC > 北京大学 > 地球与空间科学学院

	A new Ca3MgSi2O8 compound and some of its thermodynamic properties
	Bao, Xinjian ; Zhang, Yanyao ; Zhang, Zhigang ; Zhang, Lifei ; Liu, Xiaoyang ; Dong, Jianjun ; Liu, Xi
刊名	JOURNAL OF SOLID STATE CHEMISTRY
	2017
关键词	New Ca3MgSi2Os compound Single-crystal X-ray diffraction First-principles simulation Compressibility Heat capacity Standard vibrational entropy P2(1)/C-C2/C PHASE-TRANSITION X-RAY BEHAVIOR SIMULATION MERWINITE MANTLE FULL
DOI	10.1016/j.jssc.2017.08.005
英文摘要	A new calcium magnesium orthosilicate with the composition Ca3MgSi2O8 was synthesized by a solid-state reaction process at 1.2 GPa and 1373 K for 7 days. We refined the crystallographic structure of this new compound using single-crystal X-ray data, and obtained some of its thermodynamic properties by performing some first-principles simulations. Our single-crystal X-ray analysis has shown that this new compound is monoclinic with the space group C2/c, and its unit-cell parameters are a = 9.344(4) angstrom, b = 5.3308(3) angstrom, c = 13.290(6) angstrom, alpha = 90 degrees, beta = 92.072(7)degrees, gamma = 90 degrees, and V = 658.7(6) angstrom(3). The compressibility of this new compound was studied with the CASTEP code using density functional theory and planewave pseudopotential technique, which led to an isothermal bulk modulus B-0 of 99(2) GPa with a pressure derivative B-0' of 3.5(5). The phonon dispersions and vibrational density of the states (VDoS) of this new compound were calculated by using density functional perturbation theory. Subsequently, the VDoS was combined with a quasi-harmonic approximation to compute the isobaric heat capacity (C-p,) and standard vibrational entropy (S-298(0)), yielding C-p = 3.927(2) x 10(2) - 1.159(6) x 10(3)T(-0.5) - 1.054(4) x 10(7)T(-2) + 1.362(8) x 10(9)T(-3) J mol(-1) K-1 for the T range of 298-1000 K and S-298(0) = 270.5(60) J mol(-1) K-1.; Strategic Priority Research Program (B) of Chinese Academy of Sciences [XDB18000000]; DREAM project of MOST, China [2016YFC0600408]; Program of the Data Integration and Standardization in the Geological Science and Technology from MOST, China [2013FY1109000-3]; SCI(E); ARTICLE; 145-149; 255
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/470430]
专题	地球与空间科学学院
推荐引用方式 GB/T 7714	Bao, Xinjian,Zhang, Yanyao,Zhang, Zhigang,et al. A new Ca3MgSi2O8 compound and some of its thermodynamic properties[J]. JOURNAL OF SOLID STATE CHEMISTRY,2017.
APA	Bao, Xinjian.,Zhang, Yanyao.,Zhang, Zhigang.,Zhang, Lifei.,Liu, Xiaoyang.,...&Liu, Xi.(2017).A new Ca3MgSi2O8 compound and some of its thermodynamic properties.JOURNAL OF SOLID STATE CHEMISTRY.
MLA	Bao, Xinjian,et al."A new Ca3MgSi2O8 compound and some of its thermodynamic properties".JOURNAL OF SOLID STATE CHEMISTRY (2017).