Effects of Mg 2+ interstitial ion on the properties of Mg 0.5+x/2 Si 2-x Al x (PO 4 ) 3 ceramic electrolytes

• Main Authors: Halim, Z.A., Adnan, S.B.R.S., Salleh, F.M., Mohamed, N.S.
• Format: Article
• Language: English
• Published: National Engineering Research Center for Magnesium Alloys of China, Chongqing University 2017
• Subjects: Q Science (General)
• Online Access: http://eprints.um.edu.my/18986/1/Effects_of_Mg2%2B_interstitial_ion_on_the_properties.pdf; http://eprints.um.edu.my/18986/; http://dx.doi.org/10.1016/j.jma.2017.09.005

Nasicon type, Mg0.5+x/2Si2-xAlx(PO4)3 was synthesized using citric acid assisted sol-gel method. The X-ray diffraction was applied to investigate the effect of extra Mg2+ interstitial ion on the phase, unit cell parameters and structure of the samples. The Mg0.625Si1.75Al0.25(PO4)3 sample exhibited highest bulk conductivity value of 1.54 × 10−4 S cm−1 at ambient temperature. The frequency dependence of the σac 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 Mg2+ interstitial ions. The experiment results also revealed that the dielectric constant and dielectric loss decreased with frequency. The Mg0.625Si1.75Al0.25(PO4)3 was found to be electrochemically stable up to 2.51 V at ambient temperature.