Mössbauer studies and nuclear quadrupole moments of Os.

Autor: Wagner, F., Spieler, H., Kucheida, D., Kienle, P., Wäppling, R.
Zdroj: Zeitschrift für Physik; 1972, Vol. 254 Issue 2, p112-126, 15p
Abstrakt: Mössbauer transmission experiments with the 137, 155, 69 and 187 keV gamma rays ofOs, respectively, yielded the electric quadrupole splitting of these gamma resonance lines in OsO and OsP. From the results the following ratios of quadrupole moments were derived: Q(Os, 137 keV): Q(Os, 155keV): Q(Os, 187 keV): Q(Os, g.s.)=(+1.100±0.020): 1.0:(+0.863±0.051): (−0.586±0.011) and Q(Os, 69 keV)/ Q(Os, g.s.)=−0.735 ±0.012. The ratios forOs are, within their limits of error, in agreement with the expectation of the rotational model, indicating that the pairing-plusquadrupole model calculations of Kumar and Baranger predict too rapid a transition form rotational to vibrational nuclei. Applying this argument toOs in particular and using the measured ratios, one obtains a set of values for the quadrupole moments themselves, namely Q (Os)=−(1.50 ± 0.10)b, Q(Os)=−(1.36± 0.09) b, Q (Os)=−(1.18 ± 0.08) b, Q(Os)=+ (0.80 ± 0.06) b, and Q (Os)=− (0.59 ± 0.05) b. For the electric field gradient at Os nuclei in Re metal a value of V=−(3.3 ± 0.6) · 10 V/cm was found. A measurement with a magnetically split source yielded δ=+ 0.685 ± 0.025 for the E2/ M1 mixing parameter of the 69 keV transition ofOs, g/ g=0.895 ± 0.006 for the ratio of the g-factors of the 69 keV state and the groundstate, and H=−(1135 ± 20) kOe for the hyperfine field at Os nuclei in an iron matrix. [ABSTRACT FROM AUTHOR]
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