Mechanical stress and stress release channels in 10-350 nm palladium hydrogen thin films with different micro-structures

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F16%3A10334722" target="_blank" >RIV/00216208:11320/16:10334722 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.actamat.2016.05.023" target="_blank" >http://dx.doi.org/10.1016/j.actamat.2016.05.023</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.actamat.2016.05.023" target="_blank" >10.1016/j.actamat.2016.05.023</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Mechanical stress and stress release channels in 10-350 nm palladium hydrogen thin films with different micro-structures

Popis výsledku v původním jazyce

For thin metal films adhered to rigid substrates hydrogen uptake results in compressive stresses in the GPa range. Stresses affect the thermodynamics as well as the durability of thin films, but many films can release stress above critical stress values. Depending on the films' thickness, microstructure and adhesion to the substrate, which determine the energy available in the nano-sized system, stress release is conducted via different release mechanisms. To evaluate the different mechanisms, Palladium thin films ranging from 10 nm to 350 nm and with three different types of microstructures (nanocrystalline, multi oriented epitaxy and three-fold epitaxy) are studied with special focus on the mechanical stress. In-situ substrate curvature measurements, XRD stress analyses and acoustic emission (AE) measurements are conducted to determine intrinsic stresses, hydrogen-induced stress changes and stress release signals. By this complementary experimental approach, different stress release mechanisms (named channels) are identified. Discrete stress relaxation (DSR) events are found already within the overall linear elastic stress-strain regime. Energies to stimulate DSR5 lay well below the formation energy of dislocations, and may allow the movement of defects pre-existing in the films. For higher strain energies, all studied films can release stress by the formation of new dislocations and plastic deformation. When the adhesion to the substrate is small, an alternative release channel of film buckling opens for thick films.

Název v anglickém jazyce

Mechanical stress and stress release channels in 10-350 nm palladium hydrogen thin films with different micro-structures

Popis výsledku anglicky

For thin metal films adhered to rigid substrates hydrogen uptake results in compressive stresses in the GPa range. Stresses affect the thermodynamics as well as the durability of thin films, but many films can release stress above critical stress values. Depending on the films' thickness, microstructure and adhesion to the substrate, which determine the energy available in the nano-sized system, stress release is conducted via different release mechanisms. To evaluate the different mechanisms, Palladium thin films ranging from 10 nm to 350 nm and with three different types of microstructures (nanocrystalline, multi oriented epitaxy and three-fold epitaxy) are studied with special focus on the mechanical stress. In-situ substrate curvature measurements, XRD stress analyses and acoustic emission (AE) measurements are conducted to determine intrinsic stresses, hydrogen-induced stress changes and stress release signals. By this complementary experimental approach, different stress release mechanisms (named channels) are identified. Discrete stress relaxation (DSR) events are found already within the overall linear elastic stress-strain regime. Energies to stimulate DSR5 lay well below the formation energy of dislocations, and may allow the movement of defects pre-existing in the films. For higher strain energies, all studied films can release stress by the formation of new dislocations and plastic deformation. When the adhesion to the substrate is small, an alternative release channel of film buckling opens for thick films.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BM - Fyzika pevných látek a magnetismus

OECD FORD obor

—

Projekt

<a href="/cs/project/GBP108%2F12%2FG043" target="_blank" >GBP108/12/G043: Mikro- a nanokrystalické materiály s vysokým podílem rozhraní pro moderní strukturní aplikace, biodegradabilní implantáty a uchovávání vodíku</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2016

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Acta Materialia

ISSN

1359-6454

e-ISSN

—

Svazek periodika

114

Číslo periodika v rámci svazku

-

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

10

Strana od-do

116-125

Kód UT WoS článku

000378962600012

EID výsledku v databázi Scopus

2-s2.0-84969497980