TY - JOUR
T1 - In situ atomic force microscopy observation of hydrogen absorption/desorption by Palladium thin film
AU - Matsumoto, Itoko
AU - Sakaki, Kouji
AU - Nakamura, Yumiko
AU - Akiba, Etsuo
N1 - Funding Information:
This work was supported in part by the New Energy and Industrial Technology Development Organization (NEDO) under “Advanced Fundamental Research on Hydrogen Storage Materials (Hydro-Star)”. Film preparation and in-plane XRD measurements were performed at the AIST Nano-Processing Facility, supported by the Nanotechnology Network Japan of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan.
PY - 2011/12/1
Y1 - 2011/12/1
N2 - Grain structure changes in Pd thin film during hydrogen absorption and desorption were observed by in situ atomic force microscopy. The as-sputtered film had a smooth flat surface with 20-30 nm grains. Film that absorbed hydrogen showed buckling, caused by the compressive stress due to lattice expansion as Pd metal reacted with hydrogen to form the hydride. Grains on the buckles were agglomerated and deformed unlike those on flat areas beside the buckles. Film that absorbed and then desorbed hydrogen still showed some buckling; however, many buckles shrank and flattened when the compressive stress of lattice expansion was released during desorption. On both the remaining and the shrunken buckles, grain agglomeration was retained; whereas, the deformed grains reverted back to their original form. X-ray diffraction indicated compressive residual stress in the as-sputtered film and tensile residual stress in the film after hydrogen absorption/desorption. These results indicate that irreversible grain agglomeration is related to residual tensile stress in the film although agglomeration occurs only on the buckled areas.
AB - Grain structure changes in Pd thin film during hydrogen absorption and desorption were observed by in situ atomic force microscopy. The as-sputtered film had a smooth flat surface with 20-30 nm grains. Film that absorbed hydrogen showed buckling, caused by the compressive stress due to lattice expansion as Pd metal reacted with hydrogen to form the hydride. Grains on the buckles were agglomerated and deformed unlike those on flat areas beside the buckles. Film that absorbed and then desorbed hydrogen still showed some buckling; however, many buckles shrank and flattened when the compressive stress of lattice expansion was released during desorption. On both the remaining and the shrunken buckles, grain agglomeration was retained; whereas, the deformed grains reverted back to their original form. X-ray diffraction indicated compressive residual stress in the as-sputtered film and tensile residual stress in the film after hydrogen absorption/desorption. These results indicate that irreversible grain agglomeration is related to residual tensile stress in the film although agglomeration occurs only on the buckled areas.
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U2 - 10.1016/j.apsusc.2011.09.103
DO - 10.1016/j.apsusc.2011.09.103
M3 - Article
AN - SCOPUS:81555214105
SN - 0169-4332
VL - 258
SP - 1456
EP - 1459
JO - Applied Surface Science
JF - Applied Surface Science
IS - 4
ER -