Rhenium, having the second highest melting point among the metals, is used for refractory containers. Thermodynamic values for rhenium oxide is determined by mass spectrometry and X ray diffraction

Battles, J. E.

Edwards, R. K.

Gundersen, G. E.

English

NASA Technical Reports Server

November 1969	 Brief 69-10645 
(? )	
AEC-NASA TECH BRIEF
-I&  
AEC-NASA Tech Briefs describe innovations resulting from the research and development program 
of the U.S. AEC or from AEC-NASA interagency efforts. They are issued to encourage commercial 
application. Tech Briefs are published by NASA and may be purchased, at 15 cents each, from 
the Clearinghouse for Federal Scientific and Technical Information, Springfield, Virginia 22151. 
Mass-Spectrometric Study of the Rhenium-Oxygen System 
Rhenium, having the second-highest melting point 
(3180°C) among metals, invites many applications 
for use both for refractory containers used in high-
temperature studies, and in technologies. Its growing 
utilization for high-temperature applications has 
generated immediate need for knowledge of the ther-
modynamic properties of its compounds. Thus the 
thermodynamic values for rhenium oxide systems have 
been determined by mass spectrometry and x-ray 
diffraction. The experimental procedure, resultant 
data, and other results are reported (see ref.). 
Three solid oxides of rhenium are well established: 
the dirhenium heptoxide (Re 2 0 7 ), the trioxide (Re03), 
and the dioxide (Re0 2 ). The thermodynamic properties 
of Re207(s) have been well established from low-
temperature heat capacity, bomb calorimetry, and 
vapor-pressure measuremenls, whereas the properties 
of Re0 2 s) and Re0 3 (s) are incomplete or uncertain. 
In particular the low-temperature heat capacities of 
ReO,(s) and Re0 3 (s) have not been measured, and 
the results of vapor-pressure studies have shown con-
siderable disagreement. 
The purpose of this investigation was to examine 
in detail the equilibrium vapors over thermodynamic-
ally defined systems. The vaporization behaviors of 
the two-phase solid systems (Re + Re0 2 ) and (Re03) 
were studied by means of the Knudsen effusion 
method and mass-spectrometric observations, fol-
lowed by x-ray-diffraction identification of the 
residual phase after cooling of the material to room 
temperature. 
The vapor phase in equilibrium with each of the two 
systems is the same, primarily Re 207 (9) with only a 
minor amount (<5%) of Re0 3 (g). The condensed 
phases were identified before and after vaporization 
by x-ray-diffraction analysis. Mass-spectrometric
data were combined with the mass-loss effusion data 
to yield the following equations for the vapor pressure 
(calculated as Re207): 
For reaction 3ReO 3 (s) Re0 2(s) + Re207(9), 
log P(atm) = 12.529 ± 0.270 - [(11,913 + 173) /fl 
(612°-710°K) with 
..XH 1 ° = 54.5 ± 0.8 kcal/mole 
For reaction 7/2 Re02(s) 3 12 Re(s) + Re207(9), 
log P(atm) = 14.442 ± 0.145 - [(20,447 + 143)/fl 
(961°-1087°K) with H[ = 93.5 ± 0.7 kcal/mole 
The thermodynamic properties were recalculated to 
298°K by estimation of a constant 
..C1r, -4 cal/ 
deg. mole for the sublimation reactions 
H1 °298[ReO2(s)] = —102.8± 2.0kcal/mole

S° 298 [ ReO (s)]
 
= 13.5 ± 1.6eu 
H1 0 298 [Re0 3 s)1 =- 140.7 ± 2.0kcal/mole 
S° 298 [Re0 3 (s)J = 19.3 ± 1.5 eu 
In the course of the study, the appearance potential 
of Re 20 7 (g) was found to be 13.0 ± 0.5 eV. 
Reference: 
Battles, J. E.; Gundersen, G. E.; Edwards, R. K.: 
J. Phys. Chem., vol. 72, 1968, p. 3963. Edwards, 
R. K.: A Mass Spectrometric Study of the Rhenium 
Oxide System. Argonne National Laboratory, 15 
Dec. 1967.
(continued overleaf) 
This document was prepared under the sponsorship of the Atomic
	 liability resulting from the use of the information contained in this 
Energy Commission and/or the National Aeronautics and Space document, or warrants that the use of any information, apparatus, 
Administration. Neither the United States Government nor any per-	 method, or process disclosed in this document may not infringe pri-
son acting on behalf of the United States Government assumes any vately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19690000586 2020-03-16T18:29:16+00:00Z
Notes: 
1. This information may interest the metals industry. 
2. Inquiries concerning this information may be di-
rected to:
Office of Industrial Cooperation 
Argonne National Laboratory 
9700 South Cass Avenue 
Argonne, Illinois 60439 
Reference: B69-10645 
Source: J. E. Battles, G. E. Gundersen, 
and R. K. Edwards
Chemical Engineering Division
(ARG- 1042 1)
Patent status: 
Inquiries concerning rights for commercial use of 
this information may be made to: 
Mr. George H. Lee, Chief 
Chicago Patent Group 
U.S. Atomic Energy Commission 
Chicago Operations Office 
9800 South Cass Avenue 
Argonne, Illinois 60439
. 
. 
. 
Brief 69-10645	 Category 02


Mass-spectrometric study of the rhenium-oxygen system

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server