THE DISSOCIATION PRESSURES AND THE HEATS OF FORMATION OF THE MOLYBDENUM SILICIDES

Journal Article · Sat Oct 01 04:00:00 EDT 1960 · Journal of Physical Chemistry (U.S.)

DOI:https://doi.org/10.1021/j100839a048· OSTI ID:4143366

Searcy, A W; Tharp, A G

ABS>Silicon partial pressures for dissociation of the three molybdenum silicides were measured by the Knudsen effusion method. The heats of dissociation per gram atom of silicon vapor were calculated at 298 deg K take for Mo/sub 3/Si, 131-9 plus or minus 1.2 kcal; for Mo/sub 5/Si/sub 3/, 131.1 plus or minus 0.7 kcal; and for MoSi/sub 2/, 117.2 plus or minus 0.6 kcal. The heats of dissociation of the molybdenum silicides when combined with the heat of sublimation of silicon yielded the following heats of formation at 298 deg K: Mo/ sub 3/Si; -23.5 plus or minus 4 kcal; 1/3 Mo/sub 5/Si/sub 3/, -22.6 plus or minus 5 kcal; 1/2 MoSi/sub 2/, -13.0 plus or minus 5 kcal. (auth)

• Research Organization: Univ. of California, Berkeley; and Purdue Univ., Lafayette, Ind.
• Sponsoring Organization: USDOE
• NSA Number: NSA-15-001409
• OSTI ID: 4143366
• Journal Information: Journal of Physical Chemistry (U.S.), Journal Name: Journal of Physical Chemistry (U.S.) Vol. Vol: 64; ISSN JPCHA
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

CHEMISTRY
DECOMPOSITION
INTERMETALLIC COMPOUNDS
MOLYBDENUM COMPOUNDS
PREPARATION
PRESSURE
SILICIDES
SILICON
THERMODYNAMICS