We constructed a scanning near-field optical microscope (SNOM) on a commercially available atomic force microscopy (AFM) apparatus (SPM-9500J2; Shimadzu Corp.) to measure the stress distribution in ceramic composite materials. Features of our SNOM system are: (1) a compact SNOM head substituted for the original AFM head; (2) a wide scanning range (125 × 125 μm 2) inherited from the original scanner; (3) use of conventional shear-force regulation; (4) an optical system for the illumination-collection (I-C) mode; (5) excitation by a 488 nm line of an Ar-ion laser, and (6) light detection by photon counting or a polychromator equipped with an electronically cooled charge coupled device (CCD). This SNOM system was used to measure the surface structure and stress distribution of an Al2O 3/ZrO2 eutectic composite. We simultaneously measured topographic images and fluorescence spectra of an Al2O 3/ZrO2 eutectic composite. We estimated its peak intensity, peak position, and peak width from the fluorescence spectrum during scanning, which respectively correspond to the abundance of Al2O 3, stress in the grain, and the anisotropy of that stress. Mapping images showed that the stress and its anisotropy were weaker in the center of the Al2O3 grain than its boundary between Al 2O3 and ZrO2. That observation suggests that Al2O3 underwent intense anisotropic stress induced by volume expansion in the phase transition of ZrO2 from the cubic phase to the monoclinic phase during preparation.
- AlO /ZrO eutectic composite
- Mapping of spectral parameters
- Stress mapping
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics