The effect of aliovalent doping (La3+) upon the conductivity of 75:25 and 10:90 Li2SO4:Na2SO4 compositions was reported. No significant conductivity enhancement was observed in the case of the 75:25 composition, but the Na2SO4-rich composition exhibited considerable enhancement. This was attributed to an increased vacancy concentration. In the case of the 10:90 composition, the greatest enhancement was observed for 2mol%La2(SO4)3 doping at 225C and for 3mol%La2(SO4)3 at 395C. The Na2SO4-rich and Li2SO4-rich compositions exhibited conductivity behaviors which were consistent with those of pure Na2SO4 and pure Li2SO4, respectively.

Effect of Aliovalent Doping on the Electrical Conductivity of Li2SO4-Na2SO4. S.Gomathy, M.Shukla, P.Gopalan, A.R.Kulkarni: Materials Research Bulletin, 2001, 36[3-4], 397-406