2026-09-23T10:56:45Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/23885 2023-07-10 col_2142_8859 col_2142_5131 com_2142_8858 com_2142_234 com_2142_5130

Mochel, J.M. Contrata, Walter 2011-05-16T18:31:03Z 2011-05-16T18:31:03Z 10000-01-01 1992 The structure of solvent deposited (Au, Au-Ag, Pt) and vapor deposited (Cu) metal particles •1040 Awas swdied by electron microdiffraction in a S1EM. A CCD array recorded the microdiffraction pattems with high sensitivity and dynamic range, and low noise Microdiffraction pattems were classified according to whether they had distinct Bragg peaks, or were diffuse. Patterns with distinct Bragg peaks showed low rates of twinning, with an upper bound of •14±3% in the case of Au-Ag particles. Diffuse patterns indicate that many of the particles are highly disordered, •88% in the case of Au particles. The effects of the electron beam on Pt particles were sllldied further. Crystalline Pt particles up to 40 A in diameter became disordered after exposures ranging from less than a second up to 40 minutes. Disordered particles' diffraction patterns were dynamic, with flickers of intensity lasting •15 msec (the resolution of the video tape). Pt particles on an amorphous C substrate remained disordered ... 20 min before recrystallizing. The dynamic nature and persistance of the disordered state are reminiscent of Ajayan and Marks's quasimelting theory. Submitted by Carolyn Mead (cmead2@illinois.edu) on 2011-05-16T18:31:03Z No. of bitstreams: 1 1992_Contrata.pdf: 3107927 bytes, checksum: 048fbb93b06143477921c9e4b8f84e00 (MD5) Made available in DSpace on 2011-05-16T18:31:03Z (GMT). No. of bitstreams: 1 1992_Contrata.pdf: 3107927 bytes, checksum: 048fbb93b06143477921c9e4b8f84e00 (MD5) Previous issue date: 1992 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Carolyn Mead (cmead2@illinois.edu) on 2011-05-16T18:31:04Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:12:52-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: Thesis Thesis U of I Only 3471708 http://hdl.handle.net/2142/23885 en 1992 Walter Contrata small metal particles electron microdiffraction STEM Bragg peaks structure of deposited metal particles Structure and melting of small metal particles observed by stem microdiffraction Dissertation / Thesis text Physics Physics University of Illinois at Urbana-Champaign Dissertation Ph.D.