Thermal Expansion of Mg3B2O6 Borate

摘要

The thermal expansion of magnesium borate (Mg3B2O6) is studied by the method of X-ray thermodiffraction in the temperature range 25-1100 degrees C. The coefficients of thermal expansion are calculated as follows: alpha(a) = 13.0(5), alpha(b) = 8.5(5), alpha(c) = 8.0(5), alpha(V) = 30(1) x 10(-6)degrees C-1 at 25 degrees C; and alpha(a) = 20.0(5), alpha(b) = 13.0(5), alpha(c) = 13.0(5), alpha(V) = 46(1) x 10(-6)degrees C-1 at 1100 degrees C. The direction of the maximal thermal expansion (alpha(a)) is perpendicular to the preferred orientation of the BO3 triangles.