Revealing the hidden hyperfine interactions in ϵ -iron

Abstract

Herein, evidence for the long-sought finite hyperfine interaction in the high-pressure hexagonal close-packed ϵ-iron is gained through synchrotron radiation perturbed angular correlation spectroscopy. This method yields an energy splitting of 3.5(5)neV between the mIe=±1/2 and mIe=±3/2 nuclear sublevels of the iron-57 14.412-keV nuclear excited state at 30(1)GPa and room temperature. This energy splitting is related to a nuclear quadrupole hyperfine interaction with an electric field gradient of eq=1.2(2)×1016V/cm2. However, there is still a possibility that the splitting of the iron-57 nuclear levels is related to a modest magnetic hyperfine interaction of ca. 0.40(5)T.