摘要
Nasicon type,Mg_(0.5+x/2)Si_(2-x)Al_(x)(PO_(4))_(3) was synthesized using citric acid assisted sol-gel method.The X-ray diffraction was applied to investigate the effect of extra Mg^(2+)interstitial ion on the phase,unit cell parameters and structure of the samples.The Mg_(0.625)Si_(1.75)Al_(0.25)(PO_(4))_(3) sample exhibited highest bulk conductivity value of 1.54×10^(−4)S cm^(−1)at ambient temperature.The frequency dependence of theσac of these ceramic electrolytes follows the universal power law variation,σac(ω)=σo+Aωα.The conductivity parameters such as hopping frequencies,charge carrier concentration and mobile ion concentration proved that the increase in conductivity with x was due to the existence of Mg^(2+) interstitial ions.The experiment results also revealed that the dielectric constant and dielectric loss decreased with frequency.The Mg_(0.625)Si_(1.75)Al_(0.25)(PO_(4))_(3) was found to be electrochemically stable up to 2.51 V at ambient temperature.
基金
The authors would like to extend their gratitude toward the University of Malaya and Ministry of Education for funding this work through the Fundamental Research Grant Scheme(project no:FP006-2013B)
University of Malaya Research Grant(project no:RP013A-13AFR)
Postgraduate Research Grant(project no:PG032-2015A).
