Using an embedded single crystal in a polycrystalline matrix and quantitative electron energy loss spectroscopy, we have demonstrated that Ti-excess grain boundary nonstoichiometry can vary with the extent of boundary migration. While a slight excess in Ti was detected at the boundaries between small matrix grains, a large increase in TiBa ratio, to as much as 1.50 compared to the stoichiometric value, was present at the interface between a growing single crystal and the matrix grains when the embedded crystal grew up to a few hundred micrometers. This change in nonstoichiometry was attributed to a continuous accumulation of excessive Ti at the moving boundary during crystal growth. The present result indicates that growth kinetics can critically affect the interface chemistry in polycrystals.

1.
D.
McLean
,
Grain Boundaries in Metals
(
Clarendon
,
Oxford, UK
,
1957
).
2.
E. D.
Hondros
and
M. P.
Seah
,
Int. Met. Rev.
22
,
262
(
1977
).
3.
P.
Wynblatt
and
R. C.
Ku
,
Surf. Sci.
65
,
511
(
1977
).
4.
M. F.
Yan
,
R. M.
Cannon
, and
H. K.
Bowen
,
J. Appl. Phys.
54
,
764
(
1983
).
5.
W. Y.
Ching
and
Y. N.
Xu
,
Phys. Rev. B
59
,
12815
(
1999
).
6.
I.
Langmuir
,
J. Am. Chem. Soc.
40
,
1361
(
1918
).
7.
Y.
Ikuhara
,
P.
Thavorniti
, and
T.
Sakuma
,
Acta Mater.
45
,
5275
(
1997
).
8.
K.-I.
Kobayashi
,
O.
Wada
,
M.
Kobayashi
, and
Y.
Takada
,
J. Am. Ceram. Soc.
81
,
2071
(
1998
).
9.
K.
Matsunaga
,
H.
Nishimura
,
H.
Muto
,
T.
Yamamoto
, and
Y.
Ikuhara
,
Appl. Phys. Lett.
82
,
1179
(
2003
).
10.
N.
Shibata
,
S. J.
Pennycook
,
T. R.
Gosnell
,
G. S.
Painter
,
W. A.
Shelton
, and
P. F.
Becher
,
Nature (London)
428
,
730
(
2004
).
11.
G.
Duscher
,
M. F.
Chisholm
,
U.
Alber
, and
M.
Rühle
,
Nat. Mater.
3
,
621
(
2004
).
12.
Y.
Sato
,
T.
Mizoguchi
,
F.
Oba
,
M.
Yodogawa
,
T.
Yamamoto
, and
Y.
Ikuhara
,
Appl. Phys. Lett.
84
,
5311
(
2004
).
13.
D.
Hennings
,
Sci. Ceram.
12
,
405
(
1984
).
14.
B.-K.
Lee
,
S.-Y.
Chung
, and
S.-J. L.
Kang
,
Acta Mater.
48
,
1575
(
2000
).
15.
S.-Y.
Chung
,
D. Y.
Yoon
, and
S.-J. L.
Kang
,
Acta Mater.
50
,
3361
(
2002
).
16.
S.-Y.
Choi
,
D. Y.
Yoon
, and
S.-J. L.
Kang
,
Acta Mater.
52
,
3721
(
2004
).
17.
R. J.
Brook
, in
Ceramic Fabrication Processes
, edited by
F. F. Y.
Wang
(
Academic
,
New York
,
1976
).
19.
S.-Y.
Chung
,
S.-J. L.
Kang
, and
V. P.
Dravid
,
J. Am. Ceram. Soc.
85
,
2805
(
2002
).
20.
Y.-M.
Chiang
and
T.
Takagi
,
J. Am. Ceram. Soc.
73
,
3286
(
1990
).
21.
T.
Yamamoto
,
Y.
Ikuhara
,
K.
Hayashi
, and
T.
Sakuma
,
J. Mater. Res.
13
,
3449
(
1998
).
22.
S. B.
Lee
,
W.
Sigle
, and
M.
Rühle
,
Acta Mater.
50
,
2151
(
2002
).
You do not currently have access to this content.