Effect on Local Structure and Phase Transition of Perovskite-Type [N(CH(3))(4)](2)Zn(1-x)Cu(x)Br(4) (x = 0, 0.5, 0.7, and 1) Crystals with the Various Doping of Cu(2+) Ions

This study focused on how the local structures in pure [N(CH(3))(4)](2)ZnBr(4) crystal are affected by the partial replacement of Zn(2+) ions with Cu(2+) ions. The structures and phase transition temperatures T(C) of perovskite-type [N(CH(3))(4)](2)Zn(1-x)Cu(x)Br(4) (x = 0, 0.5, 0.7, and 1) mixed crystals were almost unchanged by the partial doping of Cu(2+) ions. The environments for the local structures of [N(CH(3))(4)](2)Zn(1-x)Cu(x)Br(4) mixed systems were studied according to differences in the chemical shifts of the (1)H magic angle spinning (MAS) NMR, (13)C cross-polarization (CP)/MAS NMR, and (14)N NMR spectra. The (1)H and (13)C NMR results showed that the local environments of (1)H and (13)C nuclei near T(C) are not affected by substituting Zn(2+) ions with Cu(2+) ions, whereas the (14)N NMR results showed that the local environment is affected near T(C). Consequently, the main indicators of the phase transition in [N(CH(3))(4)](2)Zn(1-x)Cu(x)Br(4) are related to the ferroelastic characteristics with different orientations.