Comment on Quantum paraelectric glass state in SrCu3Ti4O12 [Appl. Phys. Lett.104, 262905 (2014)]

TL;DR

This paper critiques a previous claim of quantum paraelectric glass state in SrCu3Ti4O12, arguing that the analysis was flawed and the evidence does not support the existence of such a state.

Contribution

It provides a critical analysis challenging the prior interpretation of permittivity data, clarifying misconceptions about quantum fluctuations in SrCu3Ti4O12.

Findings

Previous analysis is flawed and does not prove quantum paraelectricity.

Quantum fluctuations and relaxor-like behavior cannot coexist in the material.

The claimed quantum paraelectric glass state is not supported by the data.

Abstract

Recently, Kumar et al. [APL 104, 262905 (2014)] have reported quantum paraelectric glass state in SrCu3Ti4O12. Their analysis is based on the misconception about the effect of quantum fluctuations on paraelectric properties. There are very serious issues with their analysis of permittivity vs T data where authors tried to prove the presence of quantum paraelectricity in SrCu3Ti4O12. In the comment we have clearly affirm that the analysis presented by the authors do not prove the presence of quantum paraelectric behavior and there by the quantum paraelectric glass state. The quantum fluctuations and the frequency dependence of permittivity, showing relaxor like behavior cannot exist simultaneously.