“…3, from which the present data are confirmed to be in good agreement with those of MacEvan et al (10) and Badia et al (11), and the least Subsequently, the temperature dependence of grain boundary diffusion coefficient (D') is represented by closed circles in Fig. 4, and the least squares calculation gives (4) (12) The temperature dependence of the grain boundary diffusion coefficient obtained in this experiment is represented by a straight line as shown in Fig. 4, and the activation energy of 176.2 kJ -mol-1 calculated from the slope of it approximates the value of Kristall et al more closely than that of Lange et al, as shown in Table 4.…”