Itomic Force Microscopy of Ceramic Fibers Laee Mirror specimen Cantilever probo FIG. 2. Schematic of the atomic force microscope (AFM). of hot wax was placed on a steel magnetic where L is the length of the roughness pro- disk. Using a light microscope, dry single file and f(x)is the roughness curve. Addi- fibers were placed on the wax and allowed tional roughness parameters that were cal- to cool down Care was taken to ensure that culated are rmax, the difference between no wax was present on the surface of the fi- highest and lowest point in a given image, ber and the: fiber was completely flat(bow- and Rrms, the root-mean squared rough ng or movement of th ring AFM scanning would yield erroneous results (Fig. 3). The magnetic disk was positioned in the afm and the cantilever tip was low red close to the fiber when the cantilever descended until the cantilever touched he fiber surface. several locations were canned at the top of the fiber surface, and he scan direction was varied to ensure that a given image was not an artifact of the AFM tip After capturing the images, polynomial fits were applied to"flatten"the curved surface obtained from the afm. three-d mensional and section profiles of the fiber surface were obtained and a variety of quantitative roughness values were calcu- lated, such which is defined as: 10 um f(x)dx FIG3. Scanning electron micro h of nicalon fi bers on the magnetic disk before AFM imagingAtomic Force Microscopy of Cemmic Fibers 201 Diode V d FIG. 2. Schematic of the atomic force microscope (AFM). of hot wax was placed on a steel magnetic disk. Using a light microscope, dry single fibers were placed on the wax and allowed to cool down. Care was taken to ensure that no wax was present on the surface of the fiber and the fiber was completely flat (bowing or movement of the fiber during AFM scanning would yield erroneous results) (Fig. 3). The magnetic disk was positioned in the AFM and the cantilever tip was lowered close to the fiber. When the cantilever was close enough, the controlling computer descended until the cantilever touched the fiber surface. Several locations were scanned at the top of the fiber surface, and the scan direction was varied to ensure that a given image was not an artifact of the AFM tip. After capturing the images, polynomial fits were applied to “flatten” the curved surface obtained from the AFM. Three-dimensional and section profiles of the fiber surface were obtained and a variety of quantitative roughness values were calculated, such as the mean roughness, R,, which is defined as: L R, = ;jf(x)dx (1) 0 where L is the length of the roughness profile and f(x) is the roughness curve. Additional roughness parameters that were calculated are R,,,, the difference between highest and lowest point in a given image, and R,,,, the root-mean squared roughness. FIG. 3. Scanning electron micrograph of Nicalon fibers on the magnetic disk before AFM imagmg