We have studied the thermodynamics of the Mg–B system with the calculation of phase diagrams modeling technique using a computerized optimization procedure. Temperature–composition, pressure–composition, and pressure–temperature phase diagrams under different conditions are obtained. The results provide helpful insights into appropriate processing conditions for thin films of the superconducting phase, MgB2, including the identification of the pressure–temperature region for adsorption-controlled growth. Due to the high volatility of Mg, MgB2 is thermodynamically stable only under fairly high-Mg overpressures for likely growth temperatures. This places severe temperature constraints on deposition techniques employing high-vacuum conditions.

1.
J.
Nagamatsu
,
N.
Nakagawa
,
T.
Muranaka
,
Y.
Zenitani
, and
J.
Akimitsu
,
Nature (London)
410
,
63
(
2001
).
Google Scholar
 
2.
R. J.
Cava
,
Nature (London)
410
,
23
(
2001
).
Google Scholar
 
3.
S. L.
Bud’ko
,
G.
Lapertot
,
C.
Petrovic
,
C. E.
Cunningham
,
N.
Anderson
, and
P. C.
Canfield
,
Phys. Rev. Lett.
86
,
1877
(
2001
).
Google Scholar
 
4.
D. K.
Finnemore
,
J. E.
Ostenson
,
S. L.
Bud’ko
,
G.
Lapertot
, and
P. C.
Canfield
, cond-mat/0102114.
5.
J. Y. Tsao, Materials Fundamentals of Molecular Beam Epitaxy (Academic, Boston, MA, 1993).
6.
R.
Heckingbottom
,
G.
Davies
, and
K.
Prior
,
Surf. Sci.
132
,
375
(
1983
).
Google Scholar
 
7.
H.
Seki
and
A.
Koukitu
,
J. Cryst. Growth
78
,
342
(
1986
).
Google Scholar
 
8.
R. H.
Hammond
and
R.
Bormann
,
Physica C
162
,
703
(
1989
).
Google Scholar
 
9.
J. Y.
Tsao
,
J. Cryst. Growth
110
,
595
(
1991
).
Google Scholar
 
10.
C. D.
Theis
,
J.
Yeh
,
D. G.
Schlom
,
M. E.
Hawley
, and
G. W.
Brown
,
Thin Solid Films
325
,
107
(
1998
).
Google Scholar
 
11.
M.
Jones
and
R.
Marsh
,
J. Am. Chem. Soc.
76
,
1434
(
1954
).
Google Scholar
 
12.
Binary Alloy Phase Diagrams, edited by T. Massalski, 2nd ed. (ASM International, Materials Park, OH, 1990).
13.
N. Saunders and A. P. Miodownik, CALPHAD (Calculation of Phase Diagrams): A Comprehensive Guide (Pergamon, Oxford, 1998).
14.
A. T.
Dinsdale
,
CALPHAD: Comput. Coupling Phase Diagrams Thermochem.
15
,
317
(
1991
).
Google Scholar
 
15.
A. A. Nayeb-Hashemi and J. B. Clark, Phase Diagrams of Binary Magnesium Alloys (ASM International, Materials Park, OH, 1988).
16.
B.
Jansson
,
B.
Jonsson
,
B.
Sundman
, and
J.
Agren
,
Thermochim. Acta
214
,
93
(
1993
).
Google Scholar
 
17.
M. H.
Yang
and
C. P.
Flynn
,
Phys. Rev. Lett.
62
,
2476
(
1989
).
Google Scholar
 
18.
C. P.
Flynn
,
J. Phys. F: Met. Phys.
18
,
L195
(
1988
).
Google Scholar
 
19.
L. B. Loeb, The Kinetic Theory of Gases, 2nd ed. (McGraw-Hill, New York, 1934), pp. 19, 106.
20.
D. G. Schlom and J. S. Harris, Jr., in Molecular Beam Epitaxy: Applications to Key Materials, edited by R. Farrow (Noyes, Park Ridge, NJ, 1995), p. 505.
21.
Z. Y.
Fan
,
D. G.
Hinks
,
H.
Newman
, and
J. M.
Rowell
, cond-mat/0103435 (
2001
).
This content is only available via PDF.
© 2001 American Institute of Physics.
2001
American Institute of Physics
You do not currently have access to this content.