英語翻譯
Finally,we will discuss a possible mechanism for the
observed growth of single-crystalline rutile TiO2.As shown
in Fig.7,the boundary edge between the adjacent diamond
(1 0 1) and (1 1 0) facets is parallel to the ½¯111\4 direction.
This direction was parallel to the observed /1 11S and
/110S axes of the grown single-crystalline TiO2 thin
films,marked S2 and S3,respectively.This suggests that
low-index planes appear on the surrounding edge surfaces
of the grown TiO2 thin films so as to reduce the total
number of dangling bonds and to decrease the total free
energy of the concerned system.In addition,the effect of
low-energy particle beam such as the Bravais law and the
Onderdelinden channeling effect may determine the crystalline
direction of the grown single-crystalline films [1].
Because the diamond (1 1 0) facet was inclined at 601
against the incident electron beam direction when the
incident electron beam impinged parallel to the diamond
[0 1 1] direction to the rod substrate,this off-angle effect
should be considered to estimate the sizes of the singlecrystalline
TiO2 regions.The regions estimated for the
single-crystalline TiO2 thin films marked S2 and S3
were E200\2100 and E150\2140nm2 in size,respectively,
being nearly equal each other.Thus,it is concluded that the
TiO2 thin films deposited on substrates with sizes of
E2\2104nm2 by using low-energy particle beam can grow
as a single-crystalline phase.It is also found that the area of
the single-crystalline TiO2 can spread over parts of the
adjacent idiomorphic surfaces.Since any strain induced by
the lattice misfit between the substrate and overlayer
slightly increase the total free energy of the system,the
rutile TiO2 film is considered to more easily grow on a
smooth flat surface with substantially less strain energies.
Thus,it is expected that single-crystalline rutile thin films
may grow on flat substrates with larger areas than those
treated in the present study.
However,in the present study where the incident
directions of the low-energy particles were not well defined
due to usage of the polycrystalline diamond films,no reliable
relation between the growing plane direction of the overlayer
and the particle beam direction has been determined.Thus,
we should investigate in more details the threshold sizes of
the substrates for the single-crystallization,the mechanism
governing the crystalline directions,the influence of the
sputtered particle beam,and so on.