Abstract
Morphological study on the surface of sintered Cu 0.75Fe 2.25O 4, which was annealed for a long time in the condition without accompanying any crystal growth, were carried out to clarify the relation between the surface configuration and its orientation, and to determine the anisotropy value of surface free energy.
The annealing of ferrite sealed in an evacuated quartz tube resulted in the surface formed by (111) plane and continuous surface which was variously oriented near to (001). The observed surfaces were classified into three types according to the constituent plane; (1) surface formed by only continuous surfaces, (2) surface containing steps consisted of continuous surfaces and (111) planes, and (3) surface containing the steps consisted of continuous surfaces and (111) and (111) planes.
A relation between the surface orientation and surface pattern was derived and plotted in a stereographic projection triangle.
Applying the Herring equation to the diagrams which show the relation between surface configuration and its orientation, the ratios of surface free energy of continuous surface to that of (111) plane were determined as 1.37, 1.25 and 1.11 at 1050°, 1100° and 1150°C respectively.
