Volumen II - SAM

Congreso SAM/CONAMET 2009 Buenos Aires, 19 al 23 de Octubre de 2009
M2 [GPa]
1.0
0.8
0.6
0.4
0.2
0.0
300 400 500 600 700 800 900 1000 1100
T [K]
Figure 3. Experimental loss modulus data and adjusted background.
The line in Figure 4 is the HN function adjusted to the isolated loss peak. The activation energy H is 2.02 eV,
while the parameters α is close to 0.5 and β is about 0.7; the peak temperature is 834 K.
M 2 [GPa]
1.0
0.8
0.6
0.4
0.2
0.0
300 400 500 600 700 800 900 1000 1100
T [K]
Figure 4. Isolated peak and adjusted function after background subtraction.
The results for the resolved peak are in agreement with previous works on non-irradiated and neutronirradiated
samples [14]. The damping peak in the sample has a value of Q -1 (M2/M1) about 16x10 3 which is
twice larger than unirradiated and neutron irradiated samples (dose less than 1x10 -5 dpa, with 5 ppm
irradiation produced defects). This is in agreement with a larger quantity of defects produced by the
irradiation in the present work. In addition, the activation energy obtained for the loss peak is also in
agreement with previous reported works [15].
4. CONCLUSIONS
This work presents a systematic procedure for the estimation and subtraction of the background in loss
relaxation spectra. The only assumptions on the background function are quite reasonable from a physical
standpoint, namely, that the general shape of the background corresponds to the low temperature side of a
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