The influence of monovalent and bivalent cations on the electrical properties of 12-Tungstophosphoric acid salts

• Published in: Solid state ionics Vol. 176; no. 39; pp. 2881 - 2885
• Main Authors: Davidović, M., Čajkovski, T., Colomban, Ph, Mioč, U.B., Likar-Smiljanić, V., Čajkovski, D., Biljić, R., Nedić, Z.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2005
• Subjects: 12-Tungstophosphoric acid salts; 72.15.Lh; 77.20.Gm; 77.22.Ch; 78.70.Gq; Dielectric relaxations; Permittivity measurements; 72.15.Lh; 77.20.Gm; 12-Tungstophosphoric acid salts; 78.70.Gq; Dielectric relaxations; 77.22.Ch; Permittivity measurements
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2005.09.020

The effect of monovalent and bivalent cations on some electrical properties of 12-tungstophosphoric acid (WPA) salts were studied. The charge carriers in this acid are protonic entities such as H
+, OH
− and various forms of hydrated proton H(H
2O)
+
n. Conductivity, dielectric relaxations and activation energies of WPA were investigated. Permittivity measurements were performed on pressed polycrystalline pellets at lower frequencies (5 Hz–500 kHz) and in the X-band microwave range (8–12 GHz); the temperature interval was from room temperature to 360 K. In the microwave region, WPA hexahydrate (WPA-6) and some WPA salts exhibit one, two or three relaxations of the Debye type. Their relaxation times of the order of 10
−
11
s are attributed to the fast reorientation of water molecules and/or fast reorientation of oxonium ions (H
3O
+). In the lower frequency interval, dielectric relaxations of WPA-6 and some WPA salts with longer relaxation times of the order of 10
−
7
–10
−
5
s were registered and assigned to ion (H
+ and/or H
3O
+) and cation jumps.