  Ion-exchange treatment of Na2SnTeO6 in molten salt mixtures resulted in
rosiaite (PbSb2O6)-related MnSnTeO6. Its crystal structure was refined by the
Rietveld method. Of the three possible models of Sn/Te distribution, the
disordered model ((P3 Im, a = 5.23093(11) A, c = 4.62430(16) A was preferred
based on bond distances. However, it is supposed that each individual
(SnTeO6)2- layer retains complete ordering of the precursor and the apparent
disorder is only due to stacking faults. The magnetic studies have shown that
MnSnTeO6 orders antiferromagnetically at Neel temperature TN = 9.8 K. The
effective magnetic moment reasonably agrees with theoretical estimations
assuming high-spin configuration of Mn2+ (S = 5/2). Electron spin resonance
reveals spin dynamics in accordance with aniferromagnetic ordering with
critical broadening of ESR linewidth indicating the low-dimentional type of
exchange interactions. Based on the temperature and field-dependent
magnetization studies, the magnetic phase diagram of the new compound was
constructed.
