27 research outputs found
Molecular Beam Epitaxy of Wurtzite (Ga,Mn)N Films on Sapphire(0001) Showing the Ferromagnetic Behaviour at Room Temperature
Wurtzite (Ga,Mn)N films showing ferromagnetic behaviour at room temperature
were successfully grown on sapphire(0001) substrates by molecular beam epitaxy
using ammonia as nitrogen source. Magnetization measurements were carried out
by a superconducting quantum interference device at the temperatures between
1.8K and 300K with magnetic field applied parallel to the film plane up to 7T.
The magnetic-field dependence of magnetization of a (Ga,Mn)N film at 300K were
ferromagnetic, while a GaN film showed Pauli paramagnetism like behaviour. The
Curie temperatures of a (Ga,Mn)N film was estimated as 940K.Comment: 5 page
ジバチュウ ノ スイソ ゲンシヨウ レイキシ ノ ハドウ カンスウ ニ ツイテ ノ セツメンスウ ホゾンソク ノ ダトウセイ
Magnetoabsorption experiments on the A exciton in InSe have been performed in search of a unified correspondence relation between low and high magnetic field levels of a hydrogenlike state. Results show that the nodal-surface conservation rule of Shinada et al. is a more appropriate representation of this relationship than the so-called noncrossing rule.磁場中の水素原子の固有状態は解析的に解くことが不可能であるために、物理学上の永年の問題となってきた。磁場の強さが無限大の極限では無磁場のときとは量子数の全く異なる漸近解を持つことが知られているが、この強磁場極限準位に無磁場状態がどのように接続するかという疑問が問題の核心である。本研究では、InSeの励起子が物理的に理想に近い水素原子類似体であり、かつ固体効果によって水素原子に対するよりも数桁低い磁場で強磁場極限に到達しうることに着目して磁気光吸収を測定した結果、準位の接続に関して波動関数の節面数保存仮説を強く支持するデータが得られた
High TC ferromagnetism in diluted magnetic semiconducting GaN:Mn films
Wurtzite GaN:Mn films on sapphire substrates were successfully grown by use
of the molecular beam epitaxy (MBE) system. The film has an extremely high
Curie temperature of around 940 K, although the Mn concentration is only about
3 ~ 5 %. Magnetization measurements were carried out in magnetic fields
parallel to the film surface up to 7 T. The magnetization process shows the
coexistence of ferromagnetic and paramagnetic contributions at low
temperatures, while the typical ferromagnetic magnetization process is mainly
observed at high temperatures because of the decrease of the paramagnetic
contributions. The observed transport characteristics show a close relation
between the magnetism and the impurity conduction. The double exchange
mechanism of the Mn-impurity band is one of the possible models for the high-TC
ferromagnetism in GaN:Mn.Comment: 20 pages, 4 figures, submitted to Physica
ネツカガク ヲ ツクッタ ヒトビト ネツリキガク トウケイ リキガク チョウリュウドウ チョウデンドウ ノ セイカイ
知識創造物語シリーズ1The original publication is available at JAIST Press http://www.jaist.ac.jp/library/jaist-press/index.htm
Transoral surgery for superficial head and neck cancer: National Multi‐Center Survey in Japan
Head and neck cancers, especially in hypopharynx and oropharynx, are often detected at advanced stage with poor prognosis. Narrow band imaging enables detection of superficial cancers and transoral surgery is performed with curative intent. However, pathological evaluation and real-world safety and clinical outcomes have not been clearly understood. The aim of this nationwide multicenter study was to investigate the safety and efficacy of transoral surgery for superficial head and neck cancer. We collected the patients with superficial head and neck squamous cell carcinoma who were treated by transoral surgery from 27 hospitals in Japan. Central pathology review was undertaken on all of the resected specimens. The primary objective was effectiveness of transoral surgery, and the secondary objective was safety including incidence and severity of adverse events. Among the 568 patients, a total of 662 lesions were primarily treated by 575 sessions of transoral surgery. The median tumor diameter was 12 mm (range 1–75) endoscopically. Among the lesions, 57.4% were diagnosed as squamous cell carcinoma in situ. The median procedure time was 48 minutes (range 2–357). Adverse events occurred in 12.7%. Life-threatening complications occurred in 0.5%, but there were no treatment-related deaths. During a median follow-up period of 46.1 months (range 1–113), the 3-year overall survival rate, relapse-free survival rate, cause-specific survival rate, and larynx-preservation survival rate were 88.1%, 84.4%, 99.6%, and 87.5%, respectively. Transoral surgery for superficial head and neck cancer offers effective minimally invasive treatment
Direct Observation of the Surface Spin Polarization in Au Nanoparticles Protected by Polymers
Bose-Einstein Condensation and Superfluidity
The original publication is available at JAIST Press http://www.jaist.ac.jp/library/jaist-press/index.htm