Site occupancy of copper and gadolinium in PbMoO4 single crystals

摘要

Optical and electron‐spin resonance measurements, at 78 and 300 °K, of copper‐doped lead molybdate (PbMoO4) single crystals, with and without gadolinium trace impurity, have shown that: (i) Gd3+ occupies the Pb2+ substitutional site, (ii) copper enters the lattice as both Cu2+ and Cu+ in Gd‐free crystals but mostly as Cu+ in Gd‐doped crystals, and (iii) Cu2+ occupies several distinct sites, none of which has the S4 symmetry of the sites of either Pb2+ or Mo6+.