Strong anisotropic thermal expansion in oxides

被引:21
作者
Khosrovani, N
Sleight, AW
机构
[1] Oregon State Univ, Dept Chem, Corvallis, OR 97331 USA
[2] Oregon State Univ, Ctr Adv Mat Res, Corvallis, OR 97331 USA
来源
INTERNATIONAL JOURNAL OF INORGANIC MATERIALS | 1999年 / 1卷 / 01期
基金
美国国家科学基金会;
关键词
oxides; neutron scattering; crystal structure; thermal expansion;
D O I
10.1016/S1463-0176(99)00002-2
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
The strong anisotropic thermal expansion behavior found for cordierite ((Mg2Al4Si5O15), beta-eucryptite (LiAlSiO4) and NZP (NaZr2P3O12) is qualitatively rationalized using distance least squares (DLS) modeling. In this approach, the thermal expansion is driven by the ionic bonds of Mg2+, Li+ or Na+. Due to constraints imposed by shared polyhedra edges or faces, thermal expansion of the ionic bonds expands the lattice in only one or two dimensions. Due to the connectivity in these structures, this expansion in some directions causes contraction in the other directions. The thermal expansion of beta-eucryptite was determined from powder neutron diffraction data over the temperature range 10-809 K. This revealed that the volume thermal expansion of beta-eucryprite becomes substantially more negative below room temperature than it is above room temperature. The structure was refined by the Rietveld method from data collected at 12 different temperatures. DLS modeling studies suggest that Li-O bond expansion plus movement of Li from tetrahedral to octahedral sites can explain the thermal expansion behavior above room temperature. However, such an approach cannot explain the more pronounced low-temperature negative thermal expansion, which is most likely attributable to rocking motions of AlO4 and SiO4 tetrahedra. (C) 1999 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:3 / 10
页数:8
相关论文
共 24 条
[1]   ONE-DIMENSIONAL COOPERATIVE LI-DIFFUSION IN BETA-EUCRYPTITE [J].
ALPEN, UV ;
SCHULZ, H ;
TALAT, GH ;
BOHM, H .
SOLID STATE COMMUNICATIONS, 1977, 23 (12) :911-914
[2]   PHASE-TRANSFORMATION IN NA1+XSIXZR2P3-XO12 COMPOUNDS [J].
BOILOT, JP ;
SALANIE, JP ;
DESPLANCHES, G ;
LEPOTIER, D .
MATERIALS RESEARCH BULLETIN, 1979, 14 (11) :1469-1477
[3]   DIMENSIONALITY EFFECTS OF LI DIFFUSION IN BETA-EUCRYPTITE STUDIED BY SINGLE-CRYSTAL LI NMR [J].
BRINKMANN, D ;
MALI, M ;
ROOS, J ;
SCHWEICKERT, E .
SOLID STATE IONICS, 1981, 5 (OCT) :433-436
[4]  
CHOWDRY U, 1987, ANNU REV MATER SCI, V17, P332
[5]   NMR RELAXATION IN SUPERIONIC CONDUCTOR BETA-LIALSIO4 [J].
FOLLSTAEDT, DM ;
RICHARDS, PM .
PHYSICAL REVIEW LETTERS, 1976, 37 (23) :1571-1574
[6]   THERMAL CONTRACTION OF BETA-EUCRYPTITE (LI2O.AL2O3.2SIO2) BY X-RAY AND DILATOMETER METHODS [J].
GILLERY, FH ;
BUSH, EA .
JOURNAL OF THE AMERICAN CERAMIC SOCIETY, 1959, 42 (04) :175-177
[7]  
GUTH H, 1978, UNPUB 11 INT C CRYST
[8]  
HAZEN RM, 1977, AM MINERAL, V62, P309
[9]  
HOCHELLA MF, 1979, AM MINERAL, V64, P337
[10]  
LARSON AC, 1994, LANCE