Nonexistence of NdMMgMn2O6 (M=Li, Na, K, Cs) compounds

Abstract

Reported results for four new cubic compounds NdMMgMn2O6 (M=Li, Na, K, Cs) are questionable and cast doubt on the existence of such compounds. The lattice constants and relative intensities are essentially the same regardless of the nature of M; the X-ray diffraction patterns may be indexed with the lattice constants divided by √8, which result in much better figures of merit and a=0.3861 to 0.3883 nm, close to the subcell parameter of non-stoichiometric pseudocubic NdMnO3.