Observation of Jonscher Law in AC Hopping Conduction of Electron-Doped Nanoporous Crystal 12CaO7Al2O3 in THz Frequency Range

TL;DR

This study demonstrates that AC hopping conduction in electron-doped nanoporous 12CaO7Al2O3 follows Jonscher law behavior in the THz frequency range, indicating extremely fast carrier relaxation times.

Contribution

It provides experimental evidence of Jonscher law in the THz range for a nanoporous crystal, extending understanding of hopping conduction at high frequencies.

Findings

Jonscher law applies in the THz frequency range for this material.

Hopping carriers have relaxation times faster than 1 ps.

Dielectric response can be modeled by two contributions.

Abstract

We have performed terahertz time-domain spectroscopy of carrier-doped nanoporous crystal 12CaO7Al2O3 showing the Mott variable range hopping at room temperature. The real part of the dielectric constant clearly demonstrates the nature of localized carriers. The frequency dependence of both the real and imaginary parts of the dielectric constant can be simply explained by assuming two contributions: a dielectric response by the parent compound with no carriers and an AC hopping conduction with the Jonscher law generally reported up to GHz range. The possible obedience to the Jonscher law in the THz range suggests a relaxation time of the hopping carriers much faster than 1ps in the carrier-doped 12CaO7Al2O3.