ATOMIC-FORCE MICROSCOPY OBSERVATION OF FERROELASTIC DOMAIN BOUNDARY IN GDP5O14

The surface structure of GdP5O14 (gadolinium pentaphosphate) with a fe rroelastic domain boundary is investigated by AFM (atomic force micros copy) at room temperature in air. The AFM data are obtained for a 1500 -nm-square area (400 x 400 data points) on the (100) surface of the sa mple. The domain boundary is observed as a zig-zag pattern about 300 n m in width. The contour map of the surface shows a unique surface stru cture in which hollows are aligned along the domain boundary; the holl ows have a width of about 600 nm and a depth of 2 nm. If the surface i mage indicates a strain originating from the domain boundary structure , the thickness of the ferroelastic domain wall of GdP5O14 is estimate d to be about 0.6 mum at room temperature.