YOKOYAMA Hirosumi

写真a

Affiliation

Engineering educational research section Applied Physics and Engineering Program

Title

Assistant Professor

External Link
To the head of this page.▲

Research Areas 【 display / non-display 】

  • Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering) / Electric and electronic materials

To the head of this page.▲
 

Papers 【 display / non-display 】

  • ゲル化燃焼法により作製した希土類添加 アルミン酸ストロンチウム蛍光体の応力発光特性の評価

    児玉 直弥,松本 知真,横山 宏有,境 健太郎,前田 幸治

    宮崎大学工学部紀要   ( 49 )   2020.7

    　More details

    Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

  • 硫黄とフッ素を導入したアルミン酸ストロンチウム 蛍光体の応力発光とトラップ準位との関係

    松本 知真,児玉 直弥,横山 宏有,境 健太郎,前田 幸治

    宮崎大学工学部紀要   ( 49 )   2020.7

    　More details

    Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

  • X 線照射によるホウリン酸塩蛍光体中のサマリウムイオンの価数変化

    尾前翔太,前田幸治,横山宏有,境健太郎

    宮崎大学工学部紀要   ( 48 )   2019.7

    　More details

    Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

  • アルミン酸ストロンチウム蛍光体における熱ルミネッセンス測定によるトラップ準位と応力発光強度の関係

    藤原祐,児玉直弥,松本知真,横山宏有,境健太郎,前田幸治

    宮崎大学工学部紀要   ( 48 )   2019.7

    　More details

    Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

  • Effect of Mechanoluminescence and long-lasting Phosphoresence properties in SrAl2O4:Eu, Dy on Fluorine Doping

    Naoya KOMAKI, Daiki HIRAKAWA, Hirosumi YOKOYAMA, Kentaro SAKAI, Kouji MAEDA

    Memoirs of Faculty of Engineering   2018.7

    　More details

    Language：Japanese   Publishing type：Research paper (bulletin of university, research institution)  

display all >>

To the head of this page.▲

MISC 【 display / non-display 】

  • Crystallization of Amorphous GeSe<sub>2</sub> Semiconductor by Isothermal Annealing without Light Radiation

    Kentaro Sakai, Kenji Yoshino, Atsuhiko Fukuyama, Hirosumi Yokoyama, Tetsuo Ikari, Kouji Maeda

    Japanese Journal of Applied Physics   39 ( 3A )   1058 - 1061   2000

    　More details

    Language：Japanese   Publishing type：Article, review, commentary, editorial, etc. (bulletin of university, research institution)   Publisher：社団法人応用物理学会  

    The thermal-induced crystallization process of melt-quenched amorphous GeSe2 was studied. The low-temperature (LT) form, LT-GeSe2 and the high-temperature (HT) form, HT-GeSe2 were observed with Raman spectroscopy, differential scanning calorimetry (DSC) and an X-ray diffractometer. We observed the X-ray diffraction pattern of LT-GeSe2 and identified the reflection index. The crystal parameters resembled those of LT-GeS2 crystal. The growth conditions for crystallization of LT-GeSe2 and HT-GeSe2 were clarified from the time-temperature-transformation diagram. It was found that amorphous GeSe2 crystallizes at first into LT-GeSe2 and then LT-GeSe2 changes into HT-GeSe2. The activation energy (\(E_{\rm a}\)) from amorphous GeSe2 to LT-GeSe2 is estimated to be 4.6 eV from the DSC measurement which corresponds to the boundary of the phases in the T-T-T diagram. The activation energy from LT-GeSe2 to HT-GeSe2 could not be obtained.

    DOI： 10.1143/JJAP.39.1058

To the head of this page.▲

Presentations 【 display / non-display 】

  • Sr仕込み量を変化させたアルミン酸ストロンチウム蛍光体における応力発光強度とトラップ準位の関係

    児玉直弥,横山宏有,境健太郎,前田幸治

    応用物理学会九州支部学術講演会 

    　More details

    Event date： 2020.11.28 - 2020.11.29

    Language：Japanese   Presentation type：Oral presentation (general)  

  • アルミン酸ストロンチウム蛍光体におけるストロンチウム量の応力発光に及ぼす影響

    児玉 直弥,横山 宏有,境 健太郎,前田 幸治

    応用物理学会秋季学術講演会  (オンライン開催) 

    　More details

    Event date： 2020.9.8 - 2020.9.11

    Language：Japanese   Presentation type：Oral presentation (general)  

    Venue：オンライン開催  

  • Effect of strontium content on mechano-luminescent characteristics in strontium aluminate phosphor

    Kodama Naoya, Hirosumi Yokoyama, Kentaro Sakai, Koji Maeda

    JSAP Annual Meetings Extended Abstracts  2020.8.26  The Japan Society of Applied Physics

    　More details

    Event date： 2020.8.26

    Language：Japanese   Presentation type：Oral presentation (general)  

    CiNii Research

  • 不純物添加したアルミン酸ストロンチウム蛍光体の応力発光強度とトラップ準位の活性化エネルギーの関係

    前田幸治,松本知真,児玉直弥,横山宏有,境健太郎

    応用物理学会春季学術講演会 

    　More details

    Event date： 2020.3.12

    Language：Japanese   Presentation type：Oral presentation (general)  

  • EuとDyを添加したアルミン酸ストロンチウム蛍光体の応力発光強度とトラップ準位の活性化エネルギーの関係

    松本知真,児玉直弥,前田幸治,横山宏有,境健太郎

    応用物理学会九州支部学術講演会 

    　More details

    Event date： 2019.11.23 - 2019.11.24

    Language：Japanese   Presentation type：Oral presentation (general)  

display all >>

To the head of this page.▲