The 245 keV level of 111Cd: nuclear quadrupole moment and its error bar

L. ERRICO; J. RUNCO; M. RENTERÍA

Canberra

Conferencia; Joint international conference on Hyperfine Interactions and symposium on Nuclear Quadrupole Interactions 2014; 2014

Australian National University

It hardly needs justification that the 245 keV level of 111Cd is an important one for hyperfineinteraction studies, given the prominent role of 111Cd as a TDPAC probe nucleus. This makesthe (re)assessment of the nuclear quadrupole moment of this level a recurrent topic at the recenteditions of the HFI/NQI conferences. Nobody really challenges the experimental value of0.83(13) b obtained by Herzog et al. back in 1980[1]. Since that time, the scene has changed anda comparison between Density Functional Theory based electric-field gradients and experimentalquadrupole interaction frequencies has become the method of choice for the determination ofquadrupole moments of isotopes that are relevant for hyperfine interaction methods (e.g. [2, 3]).This culminated in the value of 0.765(15) b for 111Cd, presented by Haas and Correia [4] at the2012 HFI/NQI conference.A new trend in applied Density Functional Theory, is assessing in a quantitative way the errorbar on predicted values (e.g. [5, 6]). In the present contribution we do not only try to achievea numerically completely converged value for the 111Cd quadrupole moment, we also aim atdetermining the error bar on this value. This is done by calculating the electric-field gradientat a Cd nucleus in 7 elemental solids (In, Sn, Hg, Sb, Cd, Zn, Ga) with extreme settings fornumerical accuracy. For these solids, accurate experimental quadrupole interaction frequenciesand lattice parameters are known at low temperature. Analyzing these two data sets with aproper statistical formalism, leads to (1) a ?new? prediction for the 111Cd quadrupole moment(which is in good agreement with previous values), and ? more importantly ? (2) a statisticallyjustified error bar on this quadrupole moment.[1] P. Herzog, K. Freitag, M. Reuschenbach, H. Walitzki, Z. Phys. A 294 (1980) 13[2] P. Dufek, P. Blaha, K. Schwarz, Physical Review Letters 75 (1995) 3545[3] L. Errico, G. Darriba, M. Renter´ıa, Z. Tang, H. Emmerich, S. Cottenier, Physical Review B 77 (2008)195118 (2008)[4] H. Haas and J.G. Correia, Hyperfine Interactions 198 (2010) 133[5] K. Lejaeghere, V. Van Speybroeck, G. Van Oost, S. Cottenier, Critical Reviews in Solid State andMaterials Sciences 39 (2014) 124 (open access, http://dx.doi.org/10.1080/10408436.2013.772503)[6] K. Lejaeghere, J. Jaeken, V. Van Speybroeck, S. Cottenier, Physical Review B 89 (2014) 014304Electronic address: stefaan.cottenier@ugent.be