ON SURFACE MORPHOLOGY AND COMPOSITION CHANGES OF URANIUM
SAMPLES AFTER HYDROGEN ABSORPTION
D. Chicea1, J. Dash 2
1
University Lucian Blaga, Sibiu, Romania, dan.chicea@ulbsibiu.ro,
Physics Department, Portland State University, Portland, Oregon,
U.S.A., dashj@pdx.edu
2
Experiments of loading natural uranium foils with hydrogen were done. Electrolysis
was used for loading hydrogen into uranium. The composition of the surface and near surface
of the samples was determined using EDS. Images were taken with several magnifications up
to 3.4KX. Results reveal that when low current density was used, the surface patterns changed
from granules on the surface having a typical size of 2-4 microns to pits under the surface
having a typical size under one micron. When high current density was used, the surface
changed and presented deep fissures.
The surface composition changed as a result of the hydrogen loading process.
Uranium, thorium platinum and carbon concentration were measured. Experiments suggest
that the amount of thorium increases on the uranium sample with the total electric charge
transported through electrolyte. The table inserted further on presents the average thorium
concentration on different locations of the processed samples.
Sample
Th, %
U nat
U-DC-1
U-DC-2
U-DC-4
0.96
1.05
1.24
1.56
Sigma Th, % Number of
spectra
0.43
14
0.37
13
0.43
13
0.63
23
Average
counts
480321
537439
522777
583748
Carbon concentration was found to decrease on the surface of the sample as the total
electric charge, transported through electrolyte, increased.
Platinum is used in electrolysis experiment as anode primarily because it does not
dissolve in electrolyte and therefore it is not electro-deposited on the cathode surface. The
results of the platinum concentration measurements on the sample surface reveal that the
platinum concentration increased dramatically as the current density increased and that
created platinum spots on the cathode surface. Work is in progress on the topic.
References
1.
2.
3.
4.
5.
6.
R. T o e nj es, H. Sc ha tz, K. L. Kr at z, B . P fe i ffer, T .C. B eer s, J . Co wa n , V . Hi ll , Tuning the
Clock, Uranium and Thorium Chronometers Applied to CS 31082-001, Astrophysical Ages and Time
Scales, ASP Conference Series, Vol. TBD, 2001.
S. Ser ap hi n, D . Zho u , J . J iao , M . A. Mi n ke , S. W a n g, T . Yad a v, a nd J . C . W i t her s ,
Catalytic Role of Nickel, Palladium, and Platinum in the Formation of Carbon Nanoclusters, Chem. Phys.
Lett. Vol. 217, 1994, 191.
R B Ga llo wa y , Uranium and thorium series determination in natural samples by a beta-alpha
coincidence technique, Measurement Science and Technology, Volume: 1, 1990, 725.
J C F u g g le, A F B ur r , L M W at so n, D J F ab i a n a nd W La n g , X-ray photoelectron studies of
thorium and uranium, Journal of Physics F: Metal Physics, Volume: 4, 1974, 335.
I. M. C. d e Ca mar go , B ., Maz zi ll i , Determination of uranium and thorium isotopes in mineral
spring waters, Journal of Radioanalytical and Nuclear Chemistry, 212(4), 1996, 251.
Ma her M. E l -D es so u k y , Anion-exchange separation of thorium and protactinium from uranium matrix,
Mikrochimica Acta 2(5-6), 1976, 461.