HYDROGEN INDUCED PLASTIC DEFORMATION OF THIN FILMS Export

@inproceedings{citeulike:2073859, abstract = {The mechanical behavior of a thin film that is clamped to an elastically hard substrate can be compared to a bulk metal by studying the absorption of hydrogen. Since hydrogen is dissolved in interstitial sites and exerts force on neighboring metal atoms, the in-plane stresses increase with increasing hydrogen concentration. In the case of Nb-films covered with a thin Pd layer, stresses of several GPa were measured. Nb and Pd films prepared by evaporation were loaded with hydrogen. Out-of-plane strain and in-plane stresses during electrolytic loading with hydrogen were determined by performing x-ray diffraction and substrate curvature measurements. At low H-concentrations the developing stresses correspond to a clamped film expanding elastically outof- plane only. Above a critical H-concentration the films deform plastically. In some cases the critical hydrogen concentration corresponds to the terminal H-solubility, above which the hydride precipitates by emission of extrinsic dislocation loops. For the remaining cases a critical stress is reached before passing the phase boundary, which leads to the formation of misfit dislocations at the interface between film and substrate. The concomitant slip lines were observed on the surface of a Gd (0001) film using Scanning Tunneling Microscopy. An additional surface pattern that can be correlated with emitted dislocation loops was observed.}, author = {Pundt, A. and Laudahn, U. and H\"{u}lsen and Geyer, U. and Wagner, T. and Getzlaff, M. and Bode, M. and Wiesendanger, R. and Kirchheim, R.}, citeulike-article-id = {2073859}, journal = {Material Research Society Symposium Proceedings}, keywords = {deformation, film, hydrogen, nb, pd, plastic, thin}, pages = {075--85}, posted-at = {2007-12-07 16:46:41}, priority = {5}, title = {HYDROGEN INDUCED PLASTIC DEFORMATION OF THIN FILMS}, volume = {594}, year = {2000} }

TY - CONF ID - citeulike:2073859 L3 - citeulike-article-id:2073859 N2 - The mechanical behavior of a thin film that is clamped to an elastically hard substrate can be compared to a bulk metal by studying the absorption of hydrogen. Since hydrogen is dissolved in interstitial sites and exerts force on neighboring metal atoms, the in-plane stresses increase with increasing hydrogen concentration. In the case of Nb-films covered with a thin Pd layer, stresses of several GPa were measured. Nb and Pd films prepared by evaporation were loaded with hydrogen. Out-of-plane strain and in-plane stresses during electrolytic loading with hydrogen were determined by performing x-ray diffraction and substrate curvature measurements. At low H-concentrations the developing stresses correspond to a clamped film expanding elastically outof- plane only. Above a critical H-concentration the films deform plastically. In some cases the critical hydrogen concentration corresponds to the terminal H-solubility, above which the hydride precipitates by emission of extrinsic dislocation loops. For the remaining cases a critical stress is reached before passing the phase boundary, which leads to the formation of misfit dislocations at the interface between film and substrate. The concomitant slip lines were observed on the surface of a Gd (0001) film using Scanning Tunneling Microscopy. An additional surface pattern that can be correlated with emitted dislocation loops was observed. JF - Material Research Society Symposium Proceedings EP - 85 TI - HYDROGEN INDUCED PLASTIC DEFORMATION OF THIN FILMS VL - 594 SP - 075 KW - deformation KW - film KW - hydrogen KW - nb KW - pd KW - plastic KW - thin AU - Pundt, A AU - Laudahn, U AU - Hülsen AU - Geyer, U AU - Wagner, T AU - Getzlaff, M AU - Bode, M AU - Wiesendanger, R AU - Kirchheim, R PY - 2000/// ER -