Ferroelastic property of tetramethylammonium tetrachlorozincate tetrachlorocuprate, [N(CH3)4]2Zn1−xCuxCl4 (x = 0, 0.1, 0.3, 0.5, and 1)

Abstract

The various crystallographic structures of [N(CH₃)₄]₂Zn_1−xCu_xCl₄ (x = 0, 0.1, 0.3, 0.5, and 1) may be understood by considering the different chemical shifts observed in ¹H MAS and ¹³C CP/MAS NMR spectra. Cu²⁺ ions, after replacing partially the Zn²⁺ ions, occupy the same locations in the lattice as the Zn²⁺ ions. The NMR spectrum and T_1ρ of x = 0.1 and 0.3 were found to be similar to those of pure [N(CH₃)₄]₂ZnCl₄, whereas the NMR spectrum and T_1ρ of x = 0.5 were different. Consequently, the existence of ferroelastic properties of N(CH₃)₄ ions in x = 0, 0.1, 0.3, and 1 are apparent at low temperatures, whereas they disappear for x = 0.5. It has been demonstrated that the replacement of Zn²⁺ ions with high concentrations of Cu²⁺ ions changes the ferroelastic property of the crystal.