Micro-Raman spectroscopy was employed to investigate the residual strain and oxygen vacancies of BaTiO 3 -based multilayer ceramic capacitors (MLCCs) with a Ni internal electrode. Strain was found to accumulate around the internal Ni electrodes layers than at other parts of the MLCCs. In addition, the number of oxygen vacancies near the internal Ni electrode was larger than that at any other parts of the MLCCs. These observations clearly show that Raman spectroscopy is extremely useful for evaluating the residual strain and oxygen vacancies in MLCC devices.

Raman spectroscopy is used to evaluate migration behavior of oxygen vacancies in BaTiO 3 -based multilayer ceramic capacitors with Ni internal electrodes (Ni-MLCCs) before and after a highly accelerated life test (HALT). The B 1 phonon mode of BaTiO 3 that is associated with oxygen vibration was hardened and broadened near the Ni electrodes before HALT. However, the hardening and broadening of the B 1 mode were observed near the cathodes after HALT. It is considered that the oxygen vacancies were localized near the Ni electrodes before HALT and they electromigrated toward the cathode because they have the positive charges. These results show that oxygen vacancies migrated and accumulated near the cathode under a dc bias and caused insulation resistance degradation in MLCCs. In addition, Raman spectroscopy is a powerful tool for investigation of structural defect distribution including oxygen vacancies with a relatively high spatial resolution.

Raman spectroscopy is utilized to study the evaluation of vacancies in PbTiO 3 thin films subjected to hydrogen atmosphere heat treatment. The B 1 mode consisted of only oxygen ion vibration was shifted to lower frequency with increasing heat treatment temperature. It was considered that the oxygen ions were lacking from PbTiO 3 , and that oxygen vacancies were generated. It was found that the frequency of the B 1 mode is proportional to oxygen ion content. Pb ions were also lacking in the PbTiO 3 thin films with oxygen ions and the number of oxygen vacancies was larger than that of Pb ions. We suggest that the Raman spectroscopy is a suitable tool for the evaluation of oxygen vacancies in PbTiO 3 thin films.

The pathogenesis of pododermatitis circumscripta in cattle was examined. Thirty-two soles of Holstein cattle were observed. Three of them were clinically diagnosed as pododermatisis circumscripta and others appeared clinically normal. Epidermis soleae and corium soleae were observed with a scanning electron microscope. The results are as follows: Not only 3 soles with pododermatitis circumscripta but also 16 having clinically normal soles showed the following abnormal findings: 1. Hyperextension, curvature and hypertrophy on papillae coriales, 2. Vascularization and vasodilation in epidermis soleae and corium soleae and 3. Rhagades in epidermis soleae were observed. From these results, we suppose that these abnormalities are one of the first stage of pododermatitis circumscripta which might be induced from intensive feeding, abnormal hoof length and stress resulting from pregnancy or calving.