Tohoku University · 재료과학
Yuji Matsumoto 교수의 연구실은 펄스 레이저 에피택시와 분자주입 에피택시를 활용한 고정밀 편재성 반도체 및 산화물 페로일렉트릭 물질의 합성과 물성 제어를 핵심으로 합니다. 특히 투명 자성 반도체, 페로일렉트릭 산화물, 나노구조 금속 상의 성장 메커니즘을 연구하며, 나노스케일에서의 구조-물성 상관관계를 규명하고자 합니다. 고도로 제어된 표면과 인터페이스를 구현함으로써 차세대 전자 및 자기광학 소자에 응용 가능한 기능성 물질을 개발하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Dilute magnetic semiconductors and wide gap oxide semiconductors are appealing materials for magnetooptical devices. From a combinatorial screening approach looking at the solid solubility of transition metals in titanium dioxides and of their magnetic properties, we report on the observation of transparent ferromagnetism in cobalt-doped anatase thin films with theconcentration of cobalt between 0 and 8%. Magnetic microscopy images reveal a magnetic domain structure in the films, indicating the
Epitaxial TiO 2 rutile films were fabricated on α-Al 2 O 3 (1012) substrate in the layer-by-layer fashion by laser molecular beam epitaxy. Ablation with a Co-doped TiO 2 target produced single phase of rutile film with the concentration of Co between 0 and 5%. Some ferromagnetic domain structures were observed in Co x Ti 1- x O 2 rutile films by a scanning superconducting quantum interference device microscope at 3 to 90 K. The magnetic hysteresis could also be observed even at room temperature
We have developed a new combinatorial synthesis system integrating a combinatorial shadow mask into a laser MBE (molecular beam epitaxy) chamber. This combinatorial Laser MBE system can be used for fabricating a number of crystalline films with different compositions on a substrate under programmed temperature and pressure conditions. The method was applied to alloying and band gap engineering of ZnO by positional substitution of Mg into ZnO thin films. The superiority of the combinatorial metho
Abstract Excellent crystallinity of material films and atomic control of their surface/interface, sufficient for the realization of their optimal physical properties, are technological premises for modern functional‐device applications. Bi 4 Ti 3 O 12 and related compounds attract much interest as highly insulating, ferroelectric materials for use in ferroelectric random‐access memories. However, it has been difficult thus far for Bi 4 Ti 3 O 12 films to satisfy such requirements when formed usi
Growth of Ni on a c (2×2)-N Cu(100) surface was studied by scanning tunneling microscopy (STM). When Ni atoms are vaporized on a Cu(100) surface with square c (2×2)-N patches, one-atomic-layer Ni islands with an average size of 50 Å are grown on the virgin area remaining at the corner of c (2×2)-N patches, so that uniform-size Ni islands are arranged like a checkerboard. This checkerboard arrangement of Ni islands is stable up to 470 K. Stronger interaction of the Ni layer with the clean area co
