Toshio Ogawa

Ferroelectric properties of lead‐zirconate‐titanate films prepared by laser ablation

Ferroelectric lead‐zirconate‐titanate (PZT) thin films have been deposited by excimer laser ablation on sapphire substrates with and without an electrode. In preparation for the films, O2 gas pressure has greatly influenced the film structure and morphology. For the first time, we have confirmed the ferroelectric properties of PZT films prepared by laser ablation without post‐annealing. It appears to be possible to use these films for nonvolatile random access memories with some additional improvements in the film properties.

Ferroelectricity of lead-zirconate-titanate thin films prepared by laser ablation

Lead-zirconate-titanate films were prepared by excimer laser ablation. The coercive field of films deposited on MgO substrates with an electrode was lower than that of films deposited on sapphire substrates. Laser fluence influenced the grain and crystalline size, resulting in a change in the Ec. Film thicknesses were varied over a range from 0.3 to 2.41μm, with the thinnest film showing a large remanent polarization even at an applied effective voltage of 5V.

Fluctuations of Tc in YBCO thin films

Abstract Fluctuations of Tc in YBCO films were investigated using improved rf magnetron sputtering equipment. In fabricating high Tc films, the most important factor was precise control of the substrate temperature. Use of a new designed substrate holder led to films which had superior superconducting characteristics over a wide substrate area.