Although the accepted Ni-W phase diagram does not reveal the existence of h.c.p.-based phases, h.c.p.-like stacking sequences were observed in magnetron-co-sputtered Ni-W thin films at W contents of 20 to 25 at. %, by using transmission electron microscopy and X-ray diffraction. The occurrence of this h.c.p.-like solid-solution phase could be rationalized by first-principles calculations, showing that the vicinity of the system's ground-state line is populated with metastable h.c.p.-based superstructures in the intermediate concentration range from 20 to 50 at. % W. The h.c.p.-like stacking in Ni-W films was observed to be thermally persistent, up to temperatures as high as at least 850 K, as evidenced by extensive X-ray diffraction analyses on specimens before and after annealing treatments. The tendency of Ni-W for excessive planar faulting is discussed in the light of these new findings.

1.
S. B.
Maisel
,
N.
Schindzielorz
,
S.
Müller
,
H.
Reichert
, and
A.
Bosak
,
J. Appl. Crystallogr.
46
,
1211
(
2013
).
2.
R.
Reed
,
The Superalloys: Fundamentals and Applications
(
Cambridge University Press
,
2006
).
3.
M.
Nathal
and
L.
Ebert
,
Metall. Trans. A
16
,
1849
(
1985
).
4.
M.
Nathal
and
L.
Ebert
,
Metall. Trans. A
16
,
1863
(
1985
).
5.
C.
Rae
and
R.
Reed
,
Acta Mater.
49
,
4113
(
2001
).
6.
A.
Jones
,
J.
Hamann
,
A.
Lund
, and
C.
Schuh
,
Plat. Surf. Finish.
97
,
52
(
2010
), available at http://www.myvirtualpaper.com/doc/nasf_aesf/pasf_may10/2010052701/52.html#52.
7.
T. J.
Rupert
and
C. A.
Schuh
,
Acta Mater.
58
,
4137
(
2010
).
8.
U.
Welzel
,
J.
Kümmel
,
E.
Bischoff
,
S. J. B.
Kurz
, and
E. J.
Mittemeijer
,
J. Mater. Res.
26
,
2558
(
2011
).
9.
S. J. B.
Kurz
,
C.
Ensslen
,
U.
Welzel
,
A.
Leineweber
, and
E. J.
Mittemeijer
,
Scr. Mater.
69
,
65
(
2013
).
10.
R.
Cury
,
J.-M.
Joubert
,
S.
Tusseau-Nenez
,
E.
Leroy
, and
A.
Allavena-Valette
,
Intermetallics
17
,
174
(
2009
).
11.
H.
Okamoto
,
J. Phase Equilibr.
12
,
706
(
1991
).
12.
J.
Benedict
,
R.
Anderson
, and
S. J.
Klepeis
, in
MRS Online Proceedings Library
(
1991
), Vol. 254.
13.
N.
Schindzielorz
,
K.
Nowak
,
S. B.
Maisel
, and
S.
Müller
,
Acta Mater.
75
,
307
(
2014
).
14.
S. B.
Maisel
,
M.
Höfler
, and
S.
Müller
,
Nature
491
,
740
(
2012
).
15.
S.
Curtarolo
,
W.
Setyawan
,
S.
Wang
, et al.,
Comput. Mater. Sci.
58
,
227
(
2012
).
16.
G. L. W.
Hart
and
R. W.
Forcade
,
Phys. Rev. B
77
,
224115
(
2008
).
17.
G.
Kresse
and
J.
Furthmüller
,
Comput. Mater. Sci.
6
,
15
(
1996
).
18.
G.
Kresse
and
D.
Joubert
,
Phys. Rev. B
59
,
1758
(
1999
).
19.
J. P.
Perdew
,
K.
Burke
, and
M.
Ernzerhof
,
Phys. Rev. Lett.
77
,
3865
(
1996
).
20.
P. E.
Blöchl
,
Phys. Rev. B
50
,
17953
(
1994
).
21.
M.
Methfessel
and
A. T.
Paxton
,
Phys. Rev. B
40
,
3616
(
1989
).
22.
P. E.
Blöchl
,
O.
Jepsen
, and
O. K.
Andersen
,
Phys. Rev. B
49
,
16223
(
1994
).
23.
G.
Grimvall
,
B.
Magyari-Köpe
,
V.
Ozoliņš
, and
K. A.
Persson
,
Rev. Mod. Phys.
84
,
945
(
2012
).
24.
B.
Warren
,
X-Ray Diffraction
(
Addison-Wesley
,
2006
).
25.
L.
Velterop
,
R.
Delhez
,
T. H. de
Keijser
,
E. J.
Mittemeijer
, and
D.
Reefman
,
J. Appl. Crystallogr.
33
,
296
(
2000
).
26.
See supplementary material at http://dx.doi.org/10.1063/1.4894148 for SAED patterns of Ni(W) films containing 9% W and 25% W, as well as TEM images of Ni(W) films containing 9% W and 21% W.
27.
S. J. B.
Kurz
,
A.
Leineweber
, and
E. J.
Mittemeijer
, “
Anomalously high density and thermal stability of nanotwins in Ni(W) thin films: Quantitative analysis by X-ray diffraction
,”
J. Mater. Res.
(to be published).
28.
M. M. J.
Treacy
,
J. M.
Newsam
, and
M. W.
Deem
,
Proc. R. Soc. London, Ser. A
433
,
499
(
1991
).
29.
P.
Pietrokowsky
,
Nature
206
,
291
(
1965
).
30.
R. H.
Taylor
,
S.
Curtarolo
, and
G. L. W.
Hart
,
J. Am. Chem. Soc.
132
,
6851
(
2010
).
31.
J.
Larson
,
R.
Taggart
, and
D.
Polonis
,
Metall. Mater. Trans. B
1
,
485
(
1970
).
32.
H.
Okamoto
,
J. Phase Equilibr.
21
,
497
(
2000
).
33.
H.
Okamoto
,
J. Phase Equilibr.
12
,
703
(
1991
).
34.
Y.
Wang
,
C.
Woodward
,
S.
Zhou
,
Z.-K.
Liu
, and
L.-Q.
Chen
,
Scr. Mater.
52
,
17
(
2005
).
35.
T.
Tiearney
and
N.
Grant
,
Metall. Trans. A
13
,
1827
(
1982
).
36.
L.
Lu
,
Y.
Shen
,
X.
Chen
,
L.
Qian
, and
K.
Lu
,
Science
304
,
422
(
2004
).
37.
X.
Zhang
,
O.
Anderoglu
,
R.
Hoagland
, and
A.
Misra
,
JOM
60
,
75
(
2008
).
38.
C.
Shute
 et al.,
Acta Mater.
59
,
4569
(
2011
).
39.
S. J. B.
Kurz
,
U.
Welzel
,
E.
Bischoff
, and
E. J.
Mittemeijer
,
J. Appl. Crystallogr.
47
,
291
302
(
2014
).
40.
M. H. F.
Sluiter
,
Phase Transit.
80
,
299
(
2007
).

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