title: Relationships between elastic anisotropy and thermal expansion in A2Mo3O12materials.
abstract: We report calculated elastic tensors, axial Grüneisen parameters, and thermal stress distributions in Al2Mo3O12, ZrMgMo3O12, Sc2Mo3O12, and Y2Mo3O12, a series of isomorphic materials for which the coefficients of thermal expansion range from low-positive to negative. Thermal stress in polycrystalline materials arises from interactions between thermal expansion and mechanical properties, and both can be highly anisotropic. Thermal expansion anisotropy was found to be correlated with elastic anisotropy: axes with negative thermal expansion were less compliant. Calculations of axial Grüneisen parameters revealed that the thermal expansion anisotropy in these materials is in part due to the Poisson effect. Models of thermal stress due to thermal expansion anisotropy in polycrystals following cooling showed thermal stresses of sufficient magnitude to cause microcracking in all cases. The thermal expansion anisotropy was found to couple to elastic anisotropy, decreasing the bulk coefficient of thermal expansion and leading to lognormal extremes of the thermal stress distributions.
authors: Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada. mary.anne.white@dal.ca.
authors: Carl P
authors: CP
authors: Romao
authors: Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA 15213-3890, USA and BlueQuartz Software, 400 S Pioneer Blvd, Springboro, OH 45066, USA.
authors: S P
authors: SP
authors: Donegan
authors: Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada. mary.anne.white@dal.ca and Institute for Research in Materials, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada and Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
authors: J W
authors: JW
authors: Zwanziger
authors: Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada. mary.anne.white@dal.ca and Institute for Research in Materials, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada and Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
authors: Mary Anne
authors: MA
authors: White