2022年

Deuterium Distribution in Fe/V Multi-Layered Films 

Ryota Gemma, Talaat Al-Kassab and Astrid Pundt
Molecules vol.27, 7848 (2022)


Role of atomic hydrogen supply on the onset of CO2 methanation over La-Ni based hydrogen storage alloys studied by in-situ approach

 Keito SAWAHARA, Kohei YATAGAI, Torben Boll, Astrid Pundt, Ryota GEMMA

INTERNATIONAL JOURNAL OF HYDROGEN ENERGY   vol.47  19051-19061 (2022)


Chemical characterization of Mg0.25Mn0.75-H(D) nanocomposites by Atom Probe Tomography (APT)

 Ryota Gemma, Yanshan Lu, Sascha Seils, Torben Boll, Kohta Asano 

 Journal of Alloys and Compounds  vol.896  163015 (2022)


2021年

In-situ monitoring of CO2 methanation: pressure change upon ball-milling of
LaNi5 under CO2 and H2

Keito SAWAHARA and Ryota GEMMA

Journal of Advanced Science vol.33 33107 (2021) 



2020年

Transition of rate mechanism from internal nitriding to rapid nitriding mechanism at 12.5 mol%Cr in austenitic Fe-Cr-Ni alloy system

Kuniyasu GEMMA, Masashi SATO, Masae KANDA, Ryota GEMMA, Kaoru HOSHINO, Jun-ichi KAWANO
Journal of Advanced Science vol32 32107 (2020)

The impact of nanoscale compositional variation on the properties of amorphous alloys 

Ryota Gemma, Moritz To Baben, Astrid Pundt, Vassilios Kapaklis, Bjorgvin Hjorvarsson
SCIENTIFIC REPORTS 10(1) 2020年7月 

Mechanochemical CO2 methanation over LaNi-based alloys 

Kohei Yatagai, Yuto Shishido, Ryota Gemma, Torben Boll, Haru-Hisa Uchida, Kazuya Oguri
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 45(8) 5264 - 5275 2020年2月


2019年

Role of surface oxide layers in the hydrogen embrittlement of austenitic stainless steels: A TOF-SIMS study 

Chika Izawa, Stefan Wagner, Martin Deutges, Mauro Martin, Sebastian Weber, Richard Pargeter, Thorsten Michler, Haru-Hisa Uchida, Ryota Gemma, Astrid Pundt
ACTA MATERIALIA 180 329 - 340 2019年11月

Relationship between hydrogen embrittlement and M-d30 temperature: Prediction of low-nickel austenitic stainless steel's resistance 

Chika Izawa, Stefan Wagner, Martin Deutges, Mauro Martin, Sebastian Weber, Richard Pargeter, Thorsten Michler, Haru-Hisa Uchida, Ryota Gemma, Astrid Pundt
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 44(45) 25064 - 25075 2019年9月

2018年

Mechanical Composition Control for Ti-Based Hydrogen Storage Alloys 

Zholdayakova Saule, Gemma Ryota, Uchida Haru-Hisa, Sato Masashi, Matsumura Yoshihito
E-JOURNAL OF SURFACE SCIENCE AND NANOTECHNOLOGY 16 298 - 301 2018年6月21日

2017年

Laser-Induced Reversion of δ′ precipitates in an Al-Li Alloy 

Muna Khushaim, Muna Khushaim, Ryota Gemma, Talaat Al-Kassab
Microscopy and Microanalysis 23(1) 628 - 630 2017年7月1日  

2016年

Laser-Induced Reversion of delta ' Precipitates in an Al-Li Alloy: Study on Temperature Rise in Pulsed Laser Atom Probe 

Muna Khushaim, Ryota Gemma, Talaat Al-Kassab
MICROSCOPY RESEARCH AND TECHNIQUE 79(8) 727 - 737 2016年8月

2015年

Investigation of nanocrystalline Gd films loaded with hydrogen 

Petr Hruska, Jakub Cizek, Patrik Dobron, Wolfgang Anwand, Arndt Muecklich, Ryota Gemma, Stefan Wagner, Helmut Uchida, Astrid Pundt
JOURNAL OF ALLOYS AND COMPOUNDS 645 S308 - S311 2015年10月

Early Stages of Precipitation Process in Al-(Mn-)Sc-Zr Alloy Characterized by Positron Annihilation 

Martin Vlach, Jakub Cizek, Oksana Melikhova, Ivana Stulikova, Bohumil Smola, Tomas Kekule, Hana Kudrnova, Ryota Gemma, Volkmar Neubert
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE 46A(4) 1556 - 1564 2015年4月

Hydrogen-induced buckling of Pd films deposited on various substrates 

Marián Vlček, František Lukáč, Martin Vlach, Ivan Procházka, Stefan Wagner, Helmut Uchida, Astrid Pundt, Ryota Gemma, Jakub Čížek
Defect and Diffusion Forum 365 55 - 62 2015年1月1日  

~2014年

Stress release and defect occurrence in V-1_Fe-x(x) films upon hydrogen loading: H-induced superabundant vacancies, movement and creation of dislocations 

R. Gemma, P. Dobron, J. Cizek, A. Pundt
ACTA MATERIALIA 67 308 - 323 2014年4月  

Hydrogen Interaction with Defects in Nanocrystalline, Polycrystalline and Epitaxial Pd Films 

Jakub Cizek, Oksana Melikhova, Marian Vlcek, Frantisek Lukac, Martin Vlach, Patrik Dobron, Ivan Prochazka, Wolfgang Anwand, Gerhard Brauer, Stefan Wagner, Helmut Uchida, Ryota Gemma, Astrid Pundt
JOURNAL OF NANO RESEARCH 26 123 - 133 2014年 

Precipitation in cold-rolled Al-Sc-Zr and Al-Mn-Sc-Zr alloys prepared by powder metallurgy 

M. Vlach, I. Stulikova, B. Smola, T. Kekule, H. Kudrnova, S. Danis, R. Gemma, V. Ocenasek, J. Malek, D. Tanprayoon, V. Neubert
MATERIALS CHARACTERIZATION 86 59 - 68 2013年12月  

Visualization of deuterium dead layer by atom probe tomography 

Ryota Gemma, Talaat Al-Kassab, Reiner Kirchheim, Astrid Pundt
SCRIPTA MATERIALIA 67(11) 903 - 906 2012年12月 

Phase transformations in non-isothermally annealed as-cast and cold-rolled AlMnScZr alloys 

Martin Vlach, Ivana Stulikova, Bohumil Smola, Hana Cisarova, Jaroslava Piesova, Stanislav Danis, Ryota Gemma, Jaroslav Malek, Dhritti Tanprayoon, Volkmar Neubert
INTERNATIONAL JOURNAL OF MATERIALS RESEARCH 103(7) 814 - 820 2012年7月

Effect of cold rolling on precipitation processes in Al-Mn-Sc-Zr alloy 

M. Vlach, I. Stulikova, B. Smola, J. Piesova, H. Cisarova, S. Danis, J. Plasek, R. Gemma, D. Tanprayoon, V. Neubert
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING 548 27 - 32 2012年6月  

Microstructure, thermal and mechanical properties of non-isothermally annealed Al-Sc-Zr and Al-Mn-Sc-Zr alloys prepared by powder metallurgy 

M. Vlach, I. Stulíková, B. Smola, H. Císařová, J. Piešová, S. Daniš, R. Gemma, D. Tanprayoon, V. Neubert
Acta Physica Polonica A 122 439 - 443 2012年1月  

Glow discharge optical emission spectroscopy for accurate and well resolved analysis of coatings and thin films 

Marcus Wilke, Gerd Teichert, Ryota Gemma, Astrid Pundt, Reiner Kirchheim, Henry Romanus, Peter Schaaf
THIN SOLID FILMS 520(5) 1660 - 1667 2011年12月  

Analysis of deuterium in V-Fe5at.% film by atom probe tomography (APT) 

R. Gemma, T. Al-Kassab, R. Kirchheim, A. Pundt
JOURNAL OF ALLOYS AND COMPOUNDS 509 S872 - S876 2011年9月  

Hydrogen effect on dislocation nucleation in a vanadium (100) single crystal as observed during nanoindentation 

E. Tal-Gutelmacher, R. Gemma, C. A. Volkert, R. Kirchheim
SCRIPTA MATERIALIA 63(10) 1032 - 1035 2010年11月  

Hydrogen behavior in nanocrystalline titanium thin films 

E. Tal-Gutelmacher, R. Gemma, A. Pundt, R. Kirchheim
ACTA MATERIALIA 58(8) 3042 - 3049 2010年5月  

A Study on Hydrogen in Titanium Thin Films 

Ervin Tal-Gutelmacher, Ryota Gemma, Eugen Nikitin, Astrid Pundt, Reiner Kirchheim
THERMEC 2009, PTS 1-4 638-642 2950 - 2955 2010年

APT analyses of deuterium-loaded Fe/V multi-layered films 

R. Gemma, T. Al-Kassab, R. Kirchheim, A. Pundt
ULTRAMICROSCOPY 109(5) 631 - 636 2009年4月 
 

Microstructural evolution of Cu-1 at% Ti alloy aged in a hydrogen atmosphere and its relation with the electrical conductivity 

Satoshi Semboshi, Talaat Al-Kassab, Ryota Gemma, Reiner Kirchheim
ULTRAMICROSCOPY 109(5) 593 - 598 2009年4月 

Hydrogen-vacancy complexes in electron-irradiated niobium 

Jakub Cizek, Ivan Prochazka, Stanislav Danis, Gerhard Brauer, Wolfgang Anwand, Ryota Gemma, Eugen Nikitin, Reiner Kirchheim, Astrid Pundt, Rinat K. Islamgaliev
PHYSICAL REVIEW B 79(5) 2009年2月

Multi-Scale Analysis of Hydrogen-Induced Buckling in Pd Films 

J. Cizek, I. Prochazka, M. Vlach, N. Zaludova, P. Dobron, F. Chmelik, G. Brauer, W. Anwand, A. Muecklich, E. Nikitin, R. Gemma, A. Pundt, R. Kirchheim
MESOMECHANICS 2009 1(1) 99 - 103 2009年  

HYDROGEN INTERACTIONS WITH TITANIUM THIN FILMS 

E. Tal-Gutelmacher, R. Gemma, A. Pundt, R. Kirchheim
EFFECTS OF HYDROGEN ON MATERIALS 548 - 555 2009年  

Hydrogen Absorption in Ion Beam Sputtered Titanium Thin Films 

E. Tal-Gutelmacher, R. Gemma, A. Pundt, R. Kirchheim
DIFFUSION IN SOLIDS AND LIQUIDS IV 283-286 662 - 668 2009年  

Hydrogen-induced defects in Pd films 

Jakub Cizek, Ivan Prochazka, Oksana Melikhova, Martin Vlach, Nada Zaludova, Gerhard Brauer, Wolfgang Anwand, Werner Egger, Peter Sperr, Christoph Hugenschmidt, Ryota Gemma, Astrid Pundt, Reiner Kirchheim
PHYSICA STATUS SOLIDI C - CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 6, NO 11 6(11) 2364 - + 2009年  

Defect studies of hydrogen-loaded nanocrystalline Gd films 

J. Cizek, I. Prochazka, M. Vlach, N. Zaludova, S. Danis, G. Brauer, W. Anwand, A. Muecklich, R. Gemma, R. Kirchheim, A. Pundt
APPLIED SURFACE SCIENCE 255(1) 251 - 253 2008年10月  

Hydrogen-induced buckling of Pd films studied by positron annihilation 

J. Cizek, I. Prochazka, M. Vlach, N. Zaludova, S. Danis, P. Dobron, F. Chmelik, G. Brauer, W. Anwand, A. Muecklich, E. Nikitin, R. Gemma, R. Kirchheim, A. Pundt
APPLIED SURFACE SCIENCE 255(1) 241 - 244 2008年10月 
 

Nanostructural evaluation of Cu– 1at.% Ti alloy aged in a deuterium atmosphere by means of FIM and TAP methods 

S. Semboshi, R. Gemma, T. Al-Kassab, A. Pundt, R. Kirchheim
The 51st International Field Emission Symposium (51st IFES) 116 2008年6月

Defect studies of ZnO single crystals electrochemically doped with hydrogen 

J. Cizek, N. Zaludova, M. Vlach, S. Danis, J. Kuriplach, I. Prochazka, G. Brauer, W. Anwand, D. Grambole, W. Skorupa, R. Gemma, R. Kirchheim, A. Pundt
JOURNAL OF APPLIED PHYSICS 103(5) 2008年3月  

Microstructure and electrical conductivity of Cu-Ti alloys aged in hydrogen atmosphere 

S. Semboshi, R. Gemma, T. Al-Kassab, A. Pundt, R. Kirchheim
Deutsche Physilalische Gesellschaft e.V. (DPG) MM41.13 2008年2月  

Hydrogen interaction with vacancies in electron irradiated niobium 

J. Čížek, I. Procházka, G. Brauer, W. Anwand, R. Gemma, E. Nikitin, R. Kirchheim, A. Pundt
Acta Physica Polonica A 113 1293 - 1299 2008年1月1日  

Positron annihilation study of hydrogen trapping at open-volume defects: Comparison of nanocrystalline and epitaxial Nb thin films 

J. Cizek, I. Prochazka, S. Danis, O. Melikhova, M. Vlach, N. Zaludova, G. Brauer, W. Anwand, A. Muecklich, R. Gemma, E. Nikitin, R. Kirchheim, A. Pundt
JOURNAL OF ALLOYS AND COMPOUNDS 446 484 - 488 2007年10月  

Studies on hydrogen loaded V-Fe8 at% films on Al2O3 substrate 

R. Gemma, T. Al-Kassab, R. Kirchheim, A. Pundt
JOURNAL OF ALLOYS AND COMPOUNDS 446 534 - 538 2007年10月  

Defect studies of hydrogen loaded Nb: bulk metals and thin films 

J. Cizek, I. Prochazka, S. Danis, O. Melikhova, M. Vlach, N. Zaludova, G. Brauer, W. Anwand, A. Muecklich, R. Gemma, E. Nikitin, R. Kirchheim, A. Pundt
PHYSICA STATUS SOLIDI C - CURRENT TOPICS IN SOLID STATE PHYSICS, VOL 4, NO 10 4(10) 3485 - + 2007年  

Mechanically milled alanates as hydrogen storage materials 

R Genma, N Okada, T Sobue, HH Uchida
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY 31(2) 309 - 311 2006年2月  

RE-oxide doped alkaline hydrogen storage materials prepared by mechanical activation 

N Okada, R Genma, Y Nishi, HH Uchida
JOURNAL OF MATERIALS SCIENCE 39(16-17) 5503 - 5506 2004年8月  

希土類酸化物を添加したアルカリ系水素吸蔵材料の水素反応特性 

岡田 直樹, 源馬 龍太, 西 義武, 内田 晴久
日本金屬學會誌 = Journal of the Japan Institute of Metals 68(4) 223 - 227 2004年4月
  

ボールミリングにより作製したNa-Li-Al-H系水素吸蔵材料の反応性 

源馬 龍太, 岡田 直樹, 西 義武, 内田 晴久
日本金屬學會誌 67(9) 440 - 443 2003年9月  

Hydrogen reactivity of Li-containing hydrogen storage materials 

R Genma, HH Uchida, N Okada, Y Nishi
JOURNAL OF ALLOYS AND COMPOUNDS 356 358 - 362 2003年8月 

希土類酸化物を添加したアルカリ系水素吸蔵材料の水素反応特性 

岡田 直樹, 源馬 龍太, 西 義武, 内田 晴久
希土類 = Rare earths 42(42) 168 - 169 2003年5月20日  

Possibility of photo-catalytic application of paint waste from aluminum can recycling 

HH Uchida, Y Ozu, R Gemma, S Ohga, M Ohga
ENVIRONMENT CONSCIOUS MATERIALS - ECOMATERIALS 289 - 296 2000年