Hisaaki Kawade

Switching and memory phenomena in Langmuir–Blodgett films with scanning tunneling microscope

The current‐voltage characteristic has been measured for a probe/Langmuir–Blodgett (LB) film/metal structure with the scanning tunneling microscope (STM). The rapid increase of current and substantial increase in conductance have been found when a critical positive voltage was applied to the probe. A bright spot in the STM image has been observed at the position where the increase in the conductance occurred. The changes in the STM images are attributed to the change in the conductance of LB films themselves rather than the surface topography, and may be associated with the switching phenomena in LB films.

Negative resistance and electron emission in metal/Langmuir-Blodgett film/metal structures

Abstract Voltage-controlled negative resistance (VCNR) and electron emission have been observed in metal/Langmuir-Blodgett film/metal (M/LB/M) sandwich structures under vacuum. The electrons have been emitted from a complete junction area of the M/LB/M device through a top electrode with no physical damage on its surface. The emission current has been enhanced by the development of the VCNR. The results of the VCNR and the electron emission suggest that the electric conduction in the M/LB/M devices is dominated by the LB films themselves.

Aging Properties of Amorphous GdTbFeCo Magnetic Films and the Effect of Other Elements Added to Them

Tests on adding B, Bi, Al, Cr, Sm, and Cu to GdTbFeCo amorphous films revealed that B tends to reduce film deterioration and the Kerr rotation angle (¿K). Cu or small amounts of Sm lowered the amount of coercive force (Hc) deterioration, but ¿K showed no substantial change. Cr had a larger effect than Sm, and also exhibited the smallest decrease in ¿K (to 73 percent of the original value after 100 h). The addition of Cr also lowered the Curie temperature as much as 70°C at 3.6 area%.