A new intermediate intercalate in superconducting sodium-doped hafnium nitride chloride
Abstract
A new phase has been observed during the sodium intercalation of hafnium nitride chloride as intermediate between the host β-HfNCl and the already reported Na0.29HfNCl with Tc of 24 K; the new intermediate shows interlayer spacings ranging from 9.48 to 9.67 Å, corresponds to a second stage intercalate of HfNCl and is superconducting with a critical temperature of 20 K.