First investigation of ${}^{96}$Zr samples enriched by the gas-centrifuge method for the use in rare-decay studies

For the first time, the isotope ${}^{96}$Zr has been produced by the gas-centrifuge method (enrichment is 88.28% and full mass of ${}^{96}$Zr is 179.816 g). The level of radionuclide impurities of the samples and thus their suitability for rare-event search have been investigated using three low-background HPGe detectors. The most stringent limit, obtained at sea level, on the half-life of the double beta decay of ${}^{96}$Zr to the $0_1^{+}$ excited state (1148 keV) of ${}^{96}$Mo has been set $T_{1\mathrm{/}2}(0\nu +2\nu )>3.9\times {10}^{19}$ yr (90% C.L.).