Preparation of CuAlO2 Thin Films on Si or Sapphire Substrate by Sol-Gel Method Using Metal Acetate or Nitrate

Year: 2016 Volume: 10 Issue: 12 1482 - 1485 Pages

• Authors:
• Takashi Ehara
• Takayoshi Nakanishi
• Kohei Sasaki
• Marina Abe
• Hiroshi Abe
• Kiyoaki Abe
• Ryo Iizaka
• Takuya Sato

Abstract: CuAlO2 thin films are prepared on Si or sapphire substrate by sol-gel method using two kinds of sols. One is combination of Cu acetate and Al acetate basic, and the other is Cu nitrate and Al nitrate. In the case of acetate sol, XRD peaks of CuAlO2 observed at annealing temperature of 800-950 ºC on both Si and sapphire substrates. In contrast, in the case of the films prepared using nitrate on Si substrate, XRD peaks of CuAlO2 have been observed only at the annealing temperature of 800-850 ºC. At annealing temperature of 850ºC, peaks of other species have been observed beside the CuAlO2 peaks, then, the CuAlO2 peaks disappeared at annealing temperature of 900 °C with increasing in intensity of the other peaks. Intensity of the other peaks decreased at annealing temperature of 950 ºC with appearance of broad SiO2 peak. In the present, we ascribe these peaks as metal silicide.

• Keywords:
• CuAlO2
• silicide
• thin films
• transparent conducting oxide
• sol-gel.

An Investigation into Kanji Character Discrimination Process from EEG Signals

Year: 2008 Volume: 2 Issue: 6 208 - 213 Pages

• Authors:
• Hiroshi Abe
• Minoru Nakayama

Abstract: The frontal area in the brain is known to be involved in behavioral judgement. Because a Kanji character can be discriminated visually and linguistically from other characters, in Kanji character discrimination, we hypothesized that frontal event-related potential (ERP) waveforms reflect two discrimination processes in separate time periods: one based on visual analysis and the other based on lexcical access. To examine this hypothesis, we recorded ERPs while performing a Kanji lexical decision task. In this task, either a known Kanji character, an unknown Kanji character or a symbol was presented and the subject had to report if the presented character was a known Kanji character for the subject or not. The same response was required for unknown Kanji trials and symbol trials. As a preprocessing of signals, we examined the performance of a method using independent component analysis for artifact rejection and found it was effective. Therefore we used it. In the ERP results, there were two time periods in which the frontal ERP wavefoms were significantly different betweeen the unknown Kanji trials and the symbol trials: around 170ms and around 300ms after stimulus onset. This result supported our hypothesis. In addition, the result suggests that Kanji character lexical access may be fully completed by around 260ms after stimulus onset.

• Keywords:
• Character discrimination
• Event-related Potential
• IndependentComponent Analysis
• Kanji
• Lexical access.