Takuma Takahashi

Fabrication of c-axis oriented strontium barium niobate ceramics by rotating magnetic field orientation

Highly c-axis oriented Sr0.6Ba0.4Nb2O6 (SBN60) ceramics was prepared with the recent orientation method based on rotating magnetic field. Drastic improvement of piezoelectricity was noted by the c-axis orientation. The orientation increased in the sintering process through grain growth. Anisotropic microstructure was noted in the ceramics.

Pulverization of Y2O3 nanoparticles by using nanocomposite particles prepared by mechanical treatment

Abstract Nanoparticles are being extensively investigated in industries and academia due to their widespread applications in various areas of science and manufacturing. Unfortunately, nanoparticles easily aggregate. This problem of nanoparticle aggregation creates challenges for various applications. In this study, we focus on using nanocomposite particles prepared via mechanical treatment to pulverize the aggregated Y2O3 nanoparticles. CaCl2 and aggregated Y2O3 nanoparticles were mechanically treated using a process in which high shear and compressive stress are applied to them in order to generate nanocomposite particles. In order to rinse out CaCl2, the nanocomposite particles were then added to distilled water to dissolve the CaCl2 cores, and they were centrifuged before supernatant solution was decanted. The recovered Y2O3 nanoparticles had a significantly smaller particle size and larger specific surface area than the aggregates. Thus, we confirmed that the aggregated Y2O3 nanoparticles were effectively pulverized in a short time by using nanocomposites prepared by mechanical treatment. Further, the relative density of the sintered body prepared from the pulverized Y2O3 nanoparticles was higher than that of the as-received and ball-milled Y2O3 nanoparticles.