Modulated crystal structures of phases VII and V in (NH4)3H(SO4)2. Neutron Laue diffraction

A study of the crystal structure of the phases VII and V of (NH(4))(3)H(SO(4))(2) by mean of neutron Laue diffraction was carried out at temperatures from 5 to 300 K. It is found that the crystal structures of phases VII and V are incommensurately modulated with different periods, and that the phase transition from phase VII to phase V is of first order.© 2013, Springe