SODIUM MOTION IN THE NASICON RELATED NA1+XZR2-XINX(PO4)3 SOLID-SOLUTION - AN NMR-STUDY

Sodium ion motion in Na//1// plus //xZr//2// minus //xIn//x(PO//4)//3 Nasicon-related materials (0 less than equivalent to x less than equivalent to 1. 85) has been studied by NMR at two resonance frequencies from 170 to 450 K. At 8 MHz the resonance lines due to M1- and M2-type sites are well resolved. They are split by a strong second-order quadrupolar effect ( nu //Q equals 1. 5 Megacycles (Mc)/sec). For NaZr//2(PO//4)//3 only the M1 site is occupied at RT, while a new site M5 appears at rising temperature (410 K). At 21 Mc/sec the line narrowing observed at increasing temperature illustrates the Na** plus ion mobility within the skeleton. According to the temperature and the value of the ionic conductivity two diffusion mechanisms seem to occur.