Physics Letters A 318 (2003) 457–462
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Experimental observation of ordered stress patterns in iron films
deposited on silicone oil surfaces
Quan-Lin Ye, Xiao-Jun Xu, Ping-Gen Cai, A-Gen Xia, Gao-Xiang Ye
∗
Department of Physics, Zhejiang University, Hangzhou 310027, PR China
Received 5 July 2003; accepted 3 September 2003
Communicated by J. Flouquet
Abstract
We report the observations of large ordered stress patterns, namely bands, in iron films deposited on silicone oil surfaces.
The bands grow from the sample edges and then extend into the central regions of the films after deposition. The total length of
one band may be more than 5 mm. If two bands meet on their ways, they may cross each other without interference or coalesce
harmoniously. The inverse situation that one band bifurcate into two bands is also observed. The X-ray diffraction experiment
shows that the nearly free sustained iron films still exhibit polycrystalline structures and our further experiment indicates that
the bands result from the ordered aggregation of the iron crystal grains.
2003 Elsevier B.V. All rights reserved.
PACS: 62.40.+i; 68.55.-a; 68.90.+g
Keywords: Thin film; Stress pattern; Liquid substrate
1. Introduction
Vapor phase deposition of metals on liquid sub-
strates was studied in a number of recent investigations
[1–4]. The experiments show that as the nominal film
thickness increases, silver or gold atoms deposited on
liquid surfaces nucleate and form compact clusters
first. Then they diffuse and rotate randomly, which
leads to the formation of branched atomic aggregates.
*
Corresponding author.
E-mail address: gxye@mail.hz.zj.cn (G.-X. Ye).
Finally the aggregates connect one another and a con-
tinuous film forms. It is expected that the films de-
posited on liquid substrates would exhibit anomalous
properties because of their characteristic microstruc-
tures and internal stresses. Here we report a large or-
dered stress pattern existing in an iron film system de-
posited on silicone oil surfaces. The phenomena we
describe for these nearly free sustained iron films show
a distinctive effect of the weak interaction between the
metallic films and the liquid substrates, which will in
principle affect the growth mechanisms, microstruc-
tures and physical properties of various magnetic film
systems (multilayer films and superlattices, for in-
stance) not only on liquid substrates but also on soft
polymer substrates [5,6].
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doi:10.1016/j.physleta.2003.09.015