ac conductivity and NSPT model conduction of KAlP2O7 compound

Abstract

The KAlP 2 O 7 compound was prepared by conventional solid-state reaction technique. The structure is confirmed by X-ray powder diffraction. The frequency-dependent electrical properties of the sample were investigated in the temperature range of 528-668 K and in the frequency range of 209 Hz-5 MHz by impedance spectroscopy. The ac conductivity has been fitted and studied using Jonscher's equation, whose exponent s varied with the temperature, showing that the non-overlapping small polaron tunneling (NSPT) is the suitable model to describe the electrical conduction mechanism. The variation of dc conductivity suggests Arrhenius type. Besides, the modulus data were analyzed using the Kohlrausch-Williams-Watts (KWW) stretched exponential function. The peak positions ω m of the above spectra shifted towards higher frequencies with the increase in temperature. Moreover, the value of activation energy for the bulk obtained from the analysis of equivalent circuit (1.11 eV) and modulus relaxation (0.91 eV) confirms that the transport is not due to a simple hopping mechanism and that the ion transport is probably due to the hopping of K + ions along [101] tunnels direction. The thermodynamic parameters were also calculated.

Electrical properties, conduction mechanism and modulus of diphosphate compounds

“…The non-overlapping small polaron tunnelling conduction mechanism, in which the exponent s increases with increasing temperature. 11,25 The correlated barrier hopping (CBH) model, in which s decreases with increasing temperature. 20,26 The overlapping large polaron tunnelling conduction mechanism, in which the exponent s is both temperature and frequency dependent and s decreases with increasing temperature to a minimum value and then increases as the temperature increases further.…”

“…9,10 We have previously reported the electrical properties of MAlP 2 O 7 (M ¼ K, Ag, Na) compounds. [11][12][13] In the study reported here, we investigated MAlP 2 O 7 , including its electrical and dielectric properties, using impedance spectroscopy to determine the conduction mechanism. MAlP 2 O 7 can be distinguished by its crystal structure.…”

Conductivity study and correlated barrier hopping (CBH) conduction mechanism in diphosphate compound

“…Extensive research work has been made in these diphosphate compounds like KAlP 2 O 7 , CsAlP 2 O 7 , NaInP 2 O 7 , and this interesting field has been grown due to the important characterization such as optical characterization [10]. Recent works were published during last two years on diphosphate materials such as KAlP 2 O 7 , NaAlP 2 O 7 and AgFeP 2 O 7 [11,13].…”

Low-Temperature Spin-Canted Magnetism and Bipolaron Freezing Electrical Transition in Potential Electron Field Emitter NdNiO3

“…Above 300 K, the frequency exponent increases with temperature gradually and it is well consistent with the NSPT model. The frequency exponent in this region is described by , The detailed illustration of all parameters is explained in our previous paper . The lattice constant gradually expands with high temperature, and as soon as its value surpasses the polaron radius, it promotes the formation of a small polaron.…”