Scaling of superionic transition temperature in M3D(XO4)2

• Published in: Solid state ionics Vol. 225; pp. 40 - 42
• Main Authors: Matsuo, Y., Hatori, J., Kamazawa, K., Sugiyama, J., Yoshida, Y., Ikehata, S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 04.10.2012
• Subjects: Breaking; Deuteration; Hydrogen bonds; Hydrogen-bonded materials; Kinetic energy; Lattice strain; Phase transformations; Phase transition; Solid state; Superionic conductor; Transition temperature; Hydrogen-bonded materials; Superionic conductor; Phase transition
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2012.02.040

In order to clarify the role of superionic phase transition temperature in M3D(XO4)2, we have investigated the relation between a phase transition temperature TcD and a lattice strain a0. It was found that the square of a0 is proportional to TcD. This result indicates that the lattice strain is significantly important to determine the appearance of superionic conductivity. Furthermore, it was also found that the minimum kinetic energy ΔK in deuterated materials is smaller than that in hydrated materials. Considering that ΔK means the breaking energy of hydrogen bond, it is deduced that the lowering of the phase transition temperature in deuterated materials is caused by the decrease of ΔK which corresponds to the breaking energy of hydrogen bond. ► We investigate the rule of a superionic transition in M3D(XO4)2. ► We find that Tc is determined by kinetic energy, entropy and elastic energy. ► The lowering of Tc by deuteration is caused by a decrease in energy of OH⋯O.