The reclassification of Nd2-zCezCuO4 from an electron superconductor t
o a hole superconductor is suggested by simple valence and electrostat
ics arguments: In Nd2-zCezCuO4, isolated Ce substituting for Nd is not
an electron donor; the proposed actual dopant is a defect-complex of
Ce and interstitial oxygen which provides holes, making Nd2-zCezCuO4 a
hole superconductor. (C) 1998 Academic Press Limited.