Phase transition and crystal structures of BaZn2Si2O7

doi:10.1016/S0022-3697(99)00004-9

CORC > 北京大学 > 化学与分子工程学院

	Phase transition and crystal structures of BaZn2Si2O7
	Lin, JN ; Lu, GX ; Du, J ; Su, MZ ; Loong, CK ; Richardson, JW
刊名	journal of physics and chemistry of solids
	1999
关键词	crystal structure phase transitions neutron scattering inorganic compounds
DOI	10.1016/S0022-3697(99)00004-9
英文摘要	The phase transition and crystal structures of the low (LT) and high (HT) temperature phases of BaZn2Si2O7 were studied by neutron and X-ray diffraction techniques. BaZn2Si2O7 undergoes a first-order phase transition at about 250 degrees C. The LT phase of BaZn2Si2O7 is iso-structural with BaCo2Si2O7, crystallizing in the monoclinic space group C2/c with the lattice constants, a = 7.2782(43 Angstrom, b = 12.8009(7) Angstrom, c = 13.6869(7) Angstrom and beta = 90.093(6)degrees at room temperature. The structure of the HT phase, which was established by analyzing the X-lay powder-diffraction data using the direct method, crystallizes in the orthorhombic space group Ccm2(1), with the lattice constants, a = 7.6199(4) Angstrom, b = 13.0265(6) Angstrom and c = 6.7374(2)Angstrom at 280 degrees C. The underlying frameworks for both structures ale similar and can be regarded as an extensive three-dimensional tetrahedral system [Zn2Si2O7], in which both silicon and zinc atoms are coordinated tetrahedrally by oxygen atoms. The barium atoms are located within the channels of the framework, but their coordination polyhedra are different for the LT and HT structures. The lower coordination number of Ba atoms and the breaking of the Ba-O bonds in the HT phase may account for the endothermal behavior of the phase transition. The coefficient of volume expansion of the HT phase is smaller than that of the LT phase, and over the 280 degrees C-900 degrees C temperature range the cell constant along the a-axis decreases with increasing temperature. (C) 1999 Elsevier Science Ltd. All rights reserved.; Chemistry, Multidisciplinary; Physics, Condensed Matter; SCI(E); 13; ARTICLE; 7; 975-983; 60
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/215394]
专题	化学与分子工程学院
推荐引用方式 GB/T 7714	Lin, JN,Lu, GX,Du, J,et al. Phase transition and crystal structures of BaZn2Si2O7[J]. journal of physics and chemistry of solids,1999.
APA	Lin, JN,Lu, GX,Du, J,Su, MZ,Loong, CK,&Richardson, JW.(1999).Phase transition and crystal structures of BaZn2Si2O7.journal of physics and chemistry of solids.
MLA	Lin, JN,et al."Phase transition and crystal structures of BaZn2Si2O7".journal of physics and chemistry of solids (1999).