Analysis of dislocation pipe diffusion in deformed alpha-phase PdHX using a synthesized QENS approach

Using quasielastic neutron scattering results from multiple spectrometers, material considerations are made for annealed and deformed PdH_x with sufficiently low [H] as to encourage the process of dislocation pipe diffusion (DPD) below a critical temperature. The results of this analysis indicate that the simultaneous comparison of QENS results from instrument with different instrumental resolution and energy transfer window can provide a more comprehensive picture of the diffusive modes seen within a system than using the instruments independently. A method is developed for accurately comparing the dynamic structure factor S_inc(Q,E) data of multiple instruments, using an inverse Fourier transform in order to obtain the intermediate scattering function F_inc(Q,t) for each instrument and simultaneously analyzing the output from three QENS spectrometers. An array of models are approached to describe the combined F_inc(Q,t), with the best description of F_inc(Q,t) for the deformed PdH_x found to be a summed KWW/single exponential fit. The results show that the DPD contribution to the F_inc(Q,t) can be well described using a stretched exponential (KWW) mode, which is qualitatively correlated to the heterogeneity of the diffusive modes expected for the near-core and inner core region of heavily deformed Pd.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Nuclear, Plasma, Radiolgc Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2018

Author dc:creator

• Serio, Joseph Anthony

Contributors dc:contributor

• Heuser, Brent
• Zhang, Yang

• Dislocation pipe diffusion
• Hydrogen
• Palladium
• QENS
• neutron scattering

Statement dc:rights

• 2017 by Joseph Anthony Serio. All rights reserved.

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/99282

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/99282